Use of Melanocortins to Treat Insulin Sensitivity

ABSTRACT

The present invention relates to peptide ligands of the melanocortin receptors, in particular the melancortin-4 receptor, and as such, are useful in the treatment of disorders responsive to the activation of this receptor, such as insulin resistance.

This application is a continuation application of pending U.S. Ser. No. 15/242,866, filed Aug. 22, 2016, which is a continuation application of U.S. Ser. No. 14/844,128, filed Sep. 3, 2015, now U.S. Pat. No. 9,439,943, which is a continuation application of U.S. Ser. No. 14/740,917, filed May 17, 2010, now U.S. Pat. No. 9,155,777, which is a United States national filing under 35 U.S.C. § 371 of international (PCT) application No. PCT/US2008/012490, filed Nov. 5, 2008 and designating the US, which claims priority to U.S. provisional application No. 61/001,933, filed Nov. 5, 2007, each of which is hereby incorporated by reference in its entirety.

SEQUENCE LISTING

The instant application contains a Sequence Listing which has been submitted in ASCII format via EFS-Web, and is hereby incorporated by reference in its entirety. The ASCII copy is named “183P_PCT2_US-A_SeqListing_01_05May_2015_ST25.txt”, created on May 1, 2015, and has the file size of 234,000 bytes.

BACKGROUND OF THE INVENTION

Melanocortins are a family of regulatory peptides which are formed by post-translational processing of pro-hormone pro-opiomelanocortin (POMC; 131 amino acids in length). POMC is processed into three classes of hormones; the melanocortins, adrenocorticotropin hormone, and various endorphins (e.g. lipotropin) (Cone et al., Recent Prog. Horm. Res., 51:287-317, (1996); Cone et al., Ann. N.Y. Acad. Sci., 31:342-363, (1993)).

Five melanocortin receptors (MC-R) have been characterized to date. These include melanocyte-specific receptor (MC1-R), corticoadrenal-specific ACTH receptor (MC2-R), melacortin-3 (MC3-R), melanocortin-4 (MC4-R) and melanocortin-5 receptor (MC5-R). All of the melanocortin receptors respond to the peptide hormone class of melanocyte stimulating hormones (MSH) (Cone et al., Ann. N.Y. Acad. Sci., 680:342-363 (1993); Cone et al., Recent Prog. Horm. Res., 51:287-318 (1996)).

There has been great interest in melanocortin (MC-R) receptors as targets for the design of novel therapeutics to treat disorders of body weight such as obesity and cachexia. One of the receptors, MC4-R, is a 332 amino acid transmembrane protein expressed in brain as well as placental and gut tissues (Cone et al., Ann. N.Y. Acad. Sci., 680:342-363 (1993); Cone et al., Recent Prog. Horm. Res., 51:287-318 (1996)). Recent pharmacological confirmation has established that central MC4-R receptors are the prime mediators of the anorexic and orexigenic effects reported for melanocortin agonists and antagonists, respectively (Giraudo et al., Brain Res., 809:302-306 (1998); Farooqi et al., NE J Med., 348:1085-1095 (2003); MacNeil et al., Eu. J. Pharm., 44:141-157 (2002); MacNeil et al., Eu. J. Pharm., 450:93-109 (2002); Kask et al., NeuroReport, 10:707-711 (1999); Chen et al., Transgenic Res., 9:145-54, (2000); Marsh et al., Nat Genet., 21:119-22, (1999); Balthasar et al., Cell, 123:493-505 (2005)).

Complications of body weight disorders commonly include an inability to produce and utilize insulin, often resulting in faulty glucose regulation. The consequence of failure to properly control glucose metabolism affects many aspects of overall health including energy metabolism, neuropathy and heart disease. Current progress with receptor-selective melanocortin receptor ligands evidences the therapeutic potential of melanocortin receptor activation, particularly MC4-R, in the treatment of glucose regulation, including insulin metabolism.

SUMMARY OF THE INVENTION

The present invention is directed to the use of peptides which are ligands of one or more of the melanocortin receptors (MC-R), or the pharmaceutically-acceptable salts thereof, to treat mammals suffering from insulin resistance. In one embodiment, the ligands are agonists to the melanocortin 4 receptor. In a preferred embodiment, the melanocortin receptor ligands are according to the formulae described herein or are selected from particular peptides described herein.

The insulin resistant subject mammals may be obese or overweight and may lose weight as a result of the administration of the peptides of the invention. The insulin resistant subject mammals may also be normal weight or lean. The insulin resistant condition of the subject mammals may be treated independent of weight loss. In addition, the subject mammals may be human subjects of any age, such as an infant, a child, an adult or an elderly adult.

In the first embodiment, the invention provides a method to treat insulin resistance in a mammalian subject, with or without weight loss, by the administration of a therapeutically effective amount of a melanocortin receptor 4 ligand according to Formula (I) and pharmaceutically acceptable salts, hydrates, solvates or prodrugs thereof (see International Patent Application Publication Number WO 2007/008704, incorporated herein by reference in its entirety):

(R²R³)-A¹-c(A²-A³-A⁴-A⁵-A⁶-A⁷-A⁸-A⁹)-A¹⁰-R¹   (I)

wherein:

A1 is Acc, HN—(CH₂)_(m)—(C(O), L- or D-amino acid, or deleted;

A² is Cys, D-Cys, hCys, D-hCys, Pen, D-Pen, Asp, or Glu;

A³ is Gly, Ala, β-Ala, Gaba, Aib, D-amino acid, or deleted;

A⁴ is His, 2-Pal, 3-Pal, 4-Pal, Taz, 2-Thi, 3-Thi, or (X¹,X²,X³,X⁴,X⁵)Phe;

A⁵ is D-Phe, D-1-Nal, D-2-Nal, D-Trp, D-Bal, D-(X¹,X²,X³,X⁴,X⁵)Phe, L-Phe or D-(Et)Tyr;

A⁶ is Arg, hArg, Dab, Dap, Lys, Orn, or HN—CH((CH₂)_(n)—N(R⁴R⁵))—(C(O);

A⁷ is Trp, 1-Nal, 2-Nal, Bal, Bip, D-Trp, D-1-Nal, D-2-Nal, D-Bal or D-Bip;

A⁸ is Gly, D-Ala, Acc, Ala, β-Ala, Gaba, Apn, Ahx, Aha, HN—(CH₂)_(s)—(C(O), or deleted;

A⁹ is Cys, D-Cys, hCys, D-hCys, Pen, D-Pen, Dab, Dap, Orn, or Lys;

A¹⁰ is Acc, HN—(CH₂)_(t)—(C(O), L- or D-amino acid, or deleted;

R¹ is OH or NH₂;

each of R² and R³ is, independently for each occurrence, selected from the group consisting of H, (C₁-C₃₀)alkyl, (C₁-C₃₀)heteroalkyl, (C₁-C₃₀)acyl, (C₂-C₃₀)alkenyl, (C₂-C₃₀)alkynyl, aryl(C₁-C₃₀)alkyl, aryl(C₁-C₃₀)acyl, substituted (C₁-C₃₀)alkyl, substituted (C₁-C₃₀)heteroalkyl, substituted (C₁-C₃₀)acyl, substituted (C₂-C₃₀)alkenyl, substituted (C₂-C₃₀)alkynyl, substituted aryl(C₁-C₃₀)alkyl, and substituted aryl(C₁-C₃₀)acyl;

each of R⁴ and R⁵ is, independently for each occurrence, H, (C₁-C₄₀)alkyl, (C₁-C₄₀)heteroalkyl, (C₁-C₄₀)acyl, (C₂-C₄₀)alkenyl, (C₂-C₄₀)alkynyl, aryl(C₁-C₄₀)alkyl, aryl(C₁-C₄₀)acyl, substituted (C₁-C₄₀)alkyl, substituted (C₁-C₄₀)heteroalkyl, substituted (C₁-C₄₀)acyl, substituted (C₂-C₄₀)alkenyl, substituted (C₂-C₄₀)alkynyl, substituted aryl(C₁-C₄₀)alkyl, substituted aryl(C₁-C₄₀)acyl, (C₁-C₄₀)alkylsulfonyl, or —C(NH)—NH₂;

m is, independently for each occurrence, 1, 2, 3, 4, 5, 6 or 7;

n is, independently for each occurrence, 1, 2, 3, 4 or 5;

s is, independently for each occurrence, 1, 2, 3, 4, 5, 6, or 7;

t is, independently for each occurrence, 1, 2, 3, 4, 5, 6, or 7;

X¹, X², X³, X⁴, and X⁵ each is, independently for each occurrence, H, F, Cl, Br, I, (C₁₋₁₀)alkyl, substituted (C₁₋₁₀)alkyl, (C₂₋₁₀)alkenyl, substituted (C₂₋₁₀)alkenyl, (C₂₋₁₀)alkynyl, substituted (C₂₋₁₀)alkynyl, aryl, substituted aryl, OH, NH₂, NO₂, or CN; provided that

-   -   (I). when R⁴ is (C₁-C₄₀)acyl, aryl(C₁-C₄₀)acyl, substituted         (C₁-C₄₀)acyl, substituted aryl(C₁-C₄₀)acyl,         (C₁-C₄₀)alkylsulfonyl, or —C(NH)—NH₂, then R⁵ is H or         (C₁-C₄₀)alkyl, (C₁-C₄₀)heteroalkyl, (C₂-C₄₀)alkenyl,         (C₂-C₄₀)alkynyl, aryl(C₁-C₄₀)alkyl, substituted (C₁-C₄₀)alkyl,         substituted (C₁-C₄₀)heteroalkyl, substituted (C₂-C₄₀)alkenyl,         substituted (C₂-C₄₀)alkynyl, or substituted aryl(C₁-C₄₀)alkyl;     -   (II). when R² is (C₁-C₃₀)acyl, aryl(C₁-C₃₀)acyl, substituted         (C₁-C₃₀)acyl, or substituted aryl(C₁-C₃₀)acyl, then R³ is H,         (C₁-C₃₀)alkyl, (C₁-C₃₀)heteroalkyl, (C₂-C₃₀)alkenyl,         (C₂-C₃₀)alkynyl, aryl(C₁-C₃₀)alkyl, substituted (C₁-C₃₀)alkyl,         substituted (C₁-C₃₀)heteroalkyl, substituted (C₂-C₃₀)alkenyl,         substituted (C₂-C₃₀)alkynyl, or substituted aryl(C₁-C₃₀)alkyl;     -   (III). either A³ or A⁸ or both must be present in said compound;     -   (IV). when A² is Cys, D-Cys, hCys, D-hCys, Pen, or D-Pen, then         A⁹ is Cys, D-Cys, hCys, D-hCys, Pen, or D-Pen;     -   (V). when A² is Asp or Glu, then A⁹ is Dab, Dap, Orn, or Lys;     -   (VI). when A⁸ is Ala or Gly, then A¹ is not Nle; and     -   (VII). when A¹ is deleted, then R² and R³ cannot both be H;         or pharmaceutically acceptable salts thereof.

In one aspect of the first embodiment, the invention provides a method to treat insulin resistance in a mammalian subject, with or without weight loss, by the administration of a therapeutically effective amount of a subgroup of melanocortin receptor ligands of the immediate foregoing Formula I, wherein':

-   -   A¹ is A⁶c, Arg, D-Arg, Cha, D-Cha, hCha, Chg, D-Chg, Gaba, Ile,         Leu, hLeu, Met, β-hMet, 2-Nal, D-2-Nal, Nip, Nle, Oic, Phe,         D-Phe, hPhe, hPro, Val, or deleted;     -   A² is Asp, Cys, D-Cys, hCys, D-hCys, Glu, Pen, or D-Pen;     -   A³ is D-Abu, Aib, Ala, β-Ala, D-Ala, D-Cha, Gaba, D-Glu, Gly,         D-Ile, D-Leu, D-Tle, D-Val, or deleted;     -   A⁴ is His or 3-Pal;     -   A⁵ is D-Bal, D-1-Nal, D-2-Nal, D-Phe, D-Trp, or D-(Et)Tyr;     -   A⁶ is Arg, or hArg;     -   A⁷ is Bal, Bip, 1-Nal, 2-Nal, Trp, D-Trp;     -   A⁸ is A⁶c, D-Ala, Aha, Ahx, Ala, β-Ala, Apn, Gaba, Gly or         deleted;     -   A⁹ is Cys, D-Cys, hCys, D-hCys, Lys, Pen, or D-Pen;     -   A¹⁰ is Thr, or deleted;     -   wherein at least one of A³ or A⁸ is deleted, but not both,     -   or pharmaceutically acceptable salts thereof.

More preferred compounds of the immediately foregoing group of ligands according to Formula (I) useful to treat insulin resistance in a mammalian subject, with or without weight loss, are compounds of the formula:

SEQ ID NO: 1 Ac-Nle-c(Asp-His-D-Phe-Arg-Trp-β-Ala-Lys)-NH₂; SEQ ID NO: 1 Ac-Nle-c(Asp-His-D-Phe-Arg-Trp-A6c-Lys)-NH₂; SEQ ID NO: 2 Ac-Nle-c(Cys-His-D-Phe-Arg-Trp-Ahx-Cys)-NH₂; SEQ ID NO: 3 D-Phe-c(Cys-His-D-Phe-Arg-Trp-Ala-D-Cys)-Thr-NH₂; SEQ ID NO: 3 D-Phe-c(Cys-His-D-Phe-Arg-Trp-β-Ala-D-Cys)-Thr-NH₂; SEQ ID NO: 3 D-Phe-c(Cys-His-D-Phe-Arg-Trp-Gaba-D-Cys)-Thr-NH₂; SEQ ID NO: 2 Ac-Nle-c(Cys-His-D-Phe-Arg-Trp-Apn-Cys)-NH₂; SEQ ID NO: 4 Ac-Nle-c(Asp-His-D-Phe-Arg-Trp-Apn-Lys)-NH₂; SEQ ID NO: 5 Ac-A6c-c(Asp-His-D-Phe-Arg-Trp-Gaba-Lys)-NH₂; SEQ ID NO: 6 Ac-D-2-Nal-c(Asp-His-D-Phe-Arg-Trp-Gaba-Lys)-NH₂; SEQ ID NO: 6 Ac-Cha-c(Asp-His-D-Phe-Arg-Trp-Gaba-Lys)-NH₂; SEQ ID NO: 6 Ac-Nle-c(Asp-His-D-Phe-Arg-Trp-Gaba-Lys)-NH₂; SEQ ID NO: 7 Ac-Nle-c(Cys-D-Ala-His-D-Phe-Arg-Trp-Cys)-NH₂; SEQ ID NO: 7 Ac-Nle-c(Cys-β-Ala-His-D-Phe-Arg-Trp-Cys)-NH₂; SEQ ID NO: 7 Ac-Nle-c(Cys-Gaba-His-D-Phe-Arg-Trp-Cys)-NH₂; SEQ ID NO: 7 Ac-Nle-c(Cys-Aib-His-D-Phe-Arg-Trp-Cys)-NH₂; SEQ ID NO: 7 Ac-Nle-c(Cys-Gly-His-D-Phe-Arg-Trp-Cys)-NH₂; SEQ ID NO: 8 Ac-Nle-c(D-Cys-Ala-His-D-Phe-Arg-Trp-Cys)-NH₂; SEQ ID NO: 8 Ac-Nle-c(D-Cys-D-Ala-His-D-Phe-Arg-Trp-Cys)-NH₂; SEQ ID NO: 8 Ac-Nle-c(D-Cys-β-Ala-His-D-Phe-Arg-Trp-Cys)-NH₂; SEQ ID NO: 8 Ac-Nle-c(D-Cys-Gaba-His-D-Phe-Arg-Trp-Cys)-NH₂; SEQ ID NO: 8 Ac-Nle-c(D-Cys-Aib-His-D-Phe-Arg-Trp-Cys)-NH₂; SEQ ID NO: 8 Ac-Nle-c(D-Cys-Gly-His-D-Phe-Arg-Trp-Cys)-NH₂; SEQ ID NO: 9 Ac-Nle-c(Cys-D-Ala-His-D-Phe-Arg-Trp-D-Cys)-NH₂; SEQ ID NO: 9 Ac-Nle-c(Cys-β-Ala-His-D-Phe-Arg-Trp-D-Cys)-NH₂; SEQ ID NO: 9 Ac-Nle-c(Cys-Gaba-His-D-Phe-Arg-Trp-D-Cys)-NH₂; SEQ ID NO: 9 Ac-Nle-c(Cys-Aib-His-D-Phe-Arg-Trp-D-Cys)-NH₂; SEQ ID NO: 9 Ac-Nle-c(Cys-Gly-His-D-Phe-Arg-Trp-D-Cys)-NH₂; SEQ ID NO: 10 Ac-Nle-c(D-Cys-Ala-His-D-Phe-Arg-Trp-D-Cys)-NH₂; SEQ ID NO: 10 Ac-Nle-c(D-Cys-D-Ala-His-D-Phe-Arg-Trp-D-Cys)-NH₂; SEQ ID NO: 10 Ac-Nle-c(D-Cys-β-Ala-His-D-Phe-Arg-Trp-D-Cys)-NH₂; SEQ ID NO: 10 Ac-Nle-c(D-Cys-Gaba-His-D-Phe-Arg-Trp-D-Cys)-NH₂; SEQ ID NO: 10 Ac-Nle-c(D-Cys-Aib-His-D-Phe-Arg-Trp-D-Cys)-NH₂; SEQ ID NO: 11 Ac-Oic-c(Asp-His-D-Phe-Arg-Trp-Gaba-Lys)-NH₂; SEQ ID NO: 11 Ac-Chg-c(Asp-His-D-Phe-Arg-Trp-Gaba-Lys)-NH₂; SEQ ID NO: 11 Ac-hCha-c(Asp-His-D-Phe-Arg-Trp-Gaba-Lys)-NH₂; SEQ ID NO: 11 Ac-D-Cha-c(Asp-His-D-Phe-Arg-Trp-Gaba-Lys)-NH₂; SEQ ID NO: 11 Ac-Nip-c(Asp-His-D-Phe-Arg-Trp-Gaba-Lys)-NH₂; SEQ ID NO: 11 Ac-hPro-c(Asp-His-D-Phe-Arg-Trp-Gaba-Lys)-NH₂; SEQ ID NO: 11 Ac-hLeu-c(Asp-His-D-Phe-Arg-Trp-Gaba-Lys)-NH₂; SEQ ID NO: 11 Ac-hCha-c(Asp-His-D-Phe-Arg-Trp-Gaba-Lys)-NH₂; SEQ ID NO: 11 Ac-Phe-c(Asp-His-D-Phe-Arg-Trp-Gaba-Lys)-NH₂; SEQ ID NO: 11 Ac-D-Phe-c(Asp-His-D-Phe-Arg-Trp-Gaba-Lys)-NH₂; SEQ ID NO: 11 Ac-D-Chg-c(Asp-His-D-Phe-Arg-Trp-Gaba-Lys)-NH₂; SEQ ID NO: 12 n-butanoyl-Cha-c(Asp-His-D-Phe-Arg-Trp-Gaba-Lys)-NH₂; SEQ ID NO: 11 Ac-hPhe-c(Asp-His-D-Phe-Arg-Trp-Gaba-Lys)-NH₂; SEQ ID NO: 11 Ac-β-hMet-c(Asp-His-D-Phe-Arg-Trp-Gaba-Lys)-NH₂; SEQ ID NO: 11 Ac-Gaba-c(Asp-His-D-Phe-Arg-Trp-Gaba-Lys)-NH₂; SEQ ID NO: 13 Ac-Cha-c(Asp-His-D-Phe-Arg-D-Trp-Ala-Lys)-NH₂; SEQ ID NO: 13 Ac-hCha-c(Asp-His-D-Phe-Arg-D-Trp-Ala-Lys)-NH₂; SEQ ID NO: 13 Ac-Leu-c(Asp-His-D-Phe-Arg-D-Trp-Ala-Lys)-NH₂; SEQ ID NO: 13 Ac-hLeu-c(Asp-His-D-Phe-Arg-D-Trp-Ala-Lys)-NH₂; SEQ ID NO: 13 Ac-Phe-c(Asp-His-D-Phe-Arg-D-Trp-Ala-Lys)-NH₂; SEQ ID NO: 14 Ac-Nle-c(Asp-His-D-Phe-Arg-D-Trp-D-Ala-Lys)-NH₂; SEQ ID NO: 14 Ac-Nle-c(Asp-His-D-Phe-Arg-D-Trp-β-Ala-Lys)-NH₂; SEQ ID NO: 14 Ac-Nle-c(Asp-His-D-Phe-Arg-D-Trp-Gaba-Lys)-NH₂; SEQ ID NO: 14 Ac-Nle-c(Asp-His-D-Phe-Arg-D-Trp-Aha-Lys)-NH₂; SEQ ID NO: 14 Ac-Nle-c(Asp-His-D-Phe-Arg-D-Trp-Apn-Lys)-NH₂; SEQ ID NO: 15 Ac-Nle-c(Cys-His-D-Phe-Arg-D-Trp-Apn-Cys)-NH₂; SEQ ID NO: 15 Ac-Nle-c(Cys-His-D-Phe-Arg-D-Trp-Gaba-Cys)-NH₂; SEQ ID NO: 15 Ac-Nle-c(Cys-His-D-Phe-Arg-D-Trp-Ahx-Cys)-NH₂; SEQ ID NO: 15 Ac-Nle-c(Cys-His-D-Phe-Arg-D-Trp-β-Ala-Cys)-NH₂; SEQ ID NO: 15 Ac-Nle-c(Cys-His-D-Phe-Arg-D-Trp-D-Ala-Cys)-NH₂; SEQ ID NO: 16 Ac-Nle-c(Cys-D-Ala-His-D-2-Nal-Arg-Trp-Cys)-NH₂; SEQ ID NO: 16 Ac-Nle-c(Cys-D-Ala-His-D-2-Nal-Arg-2-Nal-Cys)-NH₂; SEQ ID NO: 16 Ac-Nle-c(Cys-D-Ala-His-D-2-Nal-Arg-1-Nal-Cys)-NH₂; SEQ ID NO: 17 n-butanoyl-Nle-c(Cys-D-Ala-His-D-Phe-Arg-2-Nal-Cys)-NH₂; SEQ ID NO: 17 n-butanoyl-Nle-c(Cys-D-Ala-His-D-Phe-Arg-Trp-Cys)-NH₂; SEQ ID NO: 18 Ac-Nle-c(Cys-D-Ala-His-D-Phe-Arg-2-Nal-Cys)-NH₂; SEQ ID NO: 18 Ac-Nle-c(Cys-D-Ala-His-D-Phe-Arg-1-Nal-Cys)-NH₂; SEQ ID NO: 18 Ac-Nle-c(Cys-D-Ala-His-D-Phe-Arg-Bal-Cys)-NH₂; SEQ ID NO: 61 Ac-Nle-c(Cys-D-Glu-His-D-Phe-Arg-Trp-Cys)-NH₂; SEQ ID NO: 19 Ac-Nle-c(Asp-His-D-Phe-Arg-Trp-D-Ala-Lys)-NH₂; SEQ ID NO: 20 Ac-Nle-c(Cys-D-Ala-His-D-2-Nal-Arg-Bal-Cys)-NH₂; SEQ ID NO: 21 Ac-Nle-c(Pen-D-Ala-His-D-Phe-Arg-Trp-Cys)-NH₂; SEQ ID NO: 22 Ac-Nle-c(Cys-D-Ala-His-D-Phe-Arg-Trp-Pen)-NH₂; SEQ ID NO: 22 Ac-Nle-c(Pen-D-Ala-His-D-Phe-Arg-Trp-Pen)-NH₂; SEQ ID NO: 23 D-Phe-c(Cys-His-D-Phe-hArg-Trp-β-Ala-D-Cys)-Thr-NH₂; SEQ ID NO: 24 D-Phe-c(Cys-His-D-(Et)Tyr-Arg-Trp-β-Ala-D-Cys)-Thr-NH₂; SEQ ID NO: 25 D-Phe-c(Cys-His-D-Phe-Arg-Bip-β-Ala-D-Cys)-Thr-NH₂; SEQ ID NO: 24 D-Phe-c(Cys-His-D-(Et)Tyr-hArg-Trp-β-Ala-D-Cys)-Thr-NH₂; SEQ ID NO: 26 D-Phe-c(Cys-His-D-Phe-hArg-Bip-β-Ala-D-Cys)-Thr-NH₂; SEQ ID NO: 26 D-Phe-c(Cys-His-D-(Et)Tyr-hArg-Bip-β-Ala-D-Cys)-Thr-NH₂; SEQ ID NO: 27 Nle-c(Cys-His-D-Phe-Arg-Trp-Apn-Cys)-NH₂; SEQ ID NO: 28 Ac-Nle-c(Asp-D-Ala-His-D-Phe-Arg-Trp-Lys)-NH₂; SEQ ID NO: 28 Ac-Nle-c(Asp-D-Ala-His-D-Phe-Arg-Bal-Lys)-NH₂; SEQ ID NO: 29 Ac-Nle-c(Cys-D-Ala-His-D-Phe-Arg-Trp-Pen)-OH; SEQ ID NO: 30 Ac-Nle-c(Cys-D-Abu-His-D-Phe-Arg-Trp-Cys)-NH₂; SEQ ID NO: 30 Ac-Nle-c(Cys-D-Val-His-D-Phe-Arg-Trp-Cys)-NH₂; SEQ ID NO: 30 Ac-Nle-c(Cys-D-Ile-His-D-Phe-Arg-Trp-Cys)-NH₂; SEQ ID NO: 30 Ac-Nle-c(Cys-D-Leu-His-D-Phe-Arg-Trp-Cys)-NH₂; SEQ ID NO: 30 Ac-Nle-c(Cys-D-Tle-His-D-Phe-Arg-Trp-Cys)-NH₂; SEQ ID NO: 30 Ac-Nle-c(Cys-D-Cha-His-D-Phe-Arg-Trp-Cys)-NH₂; SEQ ID NO: 31 Ac-Nle-c(Pen-His-D-Phe-Arg-Trp-Gaba-Cys)-NH₂; SEQ ID NO: 32 Ac-Nle-c(Cys-His-D-Phe-Arg-Trp-Gaba-Pen)-NH₂; SEQ ID NO: 32 Ac-Nle-c(Pen-His-D-Phe-Arg-Trp-Gaba-Pen)-NH₂; SEQ ID NO: 33 Ac-Leu-c(Cys-His-D-Phe-Arg-Trp-Gaba-Cys)-NH₂; SEQ ID NO: 33 Ac-Cha-c(Cys-His-D-Phe-Arg-Trp-Gaba-Cys)-NH₂; SEQ ID NO: 33 Ac-Ile-c(Cys-His-D-Phe-Arg-Trp-Gaba-Cys)-NH₂; SEQ ID NO: 33 Ac-Phe-c(Cys-His-D-Phe-Arg-Trp-Gaba-Cys)-NH₂; SEQ ID NO: 33 Ac-Val-c(Cys-His-D-Phe-Arg-Trp-Gaba-Cys)-NH₂; SEQ ID NO: 33 Ac-2-Nal-c(Cys-His-D-Phe-Arg-Trp-Gaba-Cys)-NH₂; SEQ ID NO: 34 Nle-c(Cys-His-D-Phe-Arg-Trp-Gaba-Cys)-NH₂; SEQ ID NO: 34 Phe-c(Cys-His-D-Phe-Arg-Trp-Gaba-Cys)-NH₂; SEQ ID NO: 35 Ac-Nle-c(Cys-3-Pal-D-Phe-Arg-Trp-Gaba-Cys)-NH₂; SEQ ID NO: 36 Ac-Nle-c(Cys-D-Ala-His-D-Phe-Arg-Trp-Cys)-OH; SEQ ID NO: 37 Ac-Nle-c(Cys-His-Phe-Arg-D-Trp-Gaba-Cys)-NH₂; SEQ ID NO: 38 Ac-Nle-c(Asp-His-D-2-Nal-Arg-Trp-Ala-Lys)-NH₂; SEQ ID NO: 38 Ac-Nle-c(Asp-His-D-2-Nal-Arg-Trp-β-Ala-Lys)-NH₂; SEQ ID NO: 39 Ac-Nle-c(Cys-His-D-2-Nal-Arg-Trp-Gaba-Cys)-NH₂; SEQ ID NO: 39 Ac-Nle-c(Cys-His-D-2-Nal-Arg-Trp-Ahx-Cys)-NH₂; SEQ ID NO: 40 Ac-hPhe-c(Asp-His-D-2-Nal-Arg-Trp-Gaba-Lys)-NH₂; SEQ ID NO: 40 Ac-Cha-c(Asp-His-D-2-Nal-Arg-Trp-Gaba-Lys)-NH₂; SEQ ID NO: 41 Ac-Nle-c(Asp-His-D-Phe-Arg-Trp-β-Ala-Lys)-OH; SEQ ID NO: 42 Ac-Nle-c(Cys-His-D-Phe-Arg-Trp-Ahx-Cys)-OH; SEQ ID NO: 43 D-Phe-c(Cys-His-D-Phe-Arg-Trp-Ala-D-Cys)-Thr-OH; SEQ ID NO: 43 D-Phe-c(Cys-His-D-Phe-Arg-Trp-β-Ala-D-Cys)-Thr-OH; SEQ ID NO: 43 D-Phe-c(Cys-His-D-Phe-Arg-Trp-Gaba-D-Cys)-Thr-OH; SEQ ID NO: 42 Ac-Nle-c(Cys-His-D-Phe-Arg-Trp-Apn-Cys)-OH; SEQ ID NO: 41 Ac-Nle-c(Asp-His-D-Phe-Arg-Trp-Apn-Lys)-OH; SEQ ID NO: 44 Ac-Cha-c(Asp-His-D-Phe-Arg-Trp-Gaba-Lys)-OH; SEQ ID NO: 44 Ac-Nle-c(Asp-His-D-Phe-Arg-Trp-Gaba-Lys)-OH; SEQ ID NO: 29 Ac-Nle-c(Cys-D-Ala-His-D-Phe-Arg-Trp-Cys)-OH; SEQ ID NO: 44 Ac-Chg-c(Asp-His-D-Phe-Arg-Trp-Gaba-Lys)-OH; SEQ ID NO: 44 Ac-D-Cha-c(Asp-His-D-Phe-Arg-Trp-Gaba-Lys)-OH; SEQ ID NO: 44 Ac-hCha-c(Asp-His-D-Phe-Arg-Trp-Gaba-Lys)-OH; SEQ ID NO: 44 Ac-D-Chg-c(Asp-His-D-Phe-Arg-Trp-Gaba-Lys)-OH; SEQ ID NO: 44 Ac-hPhe-c(Asp-His-D-Phe-Arg-Trp-Gaba-Lys)-OH; SEQ ID NO: 45 Ac-Nle-c(Cys-His-D-Phe-Arg-D-Trp-Gaba-Cys)-OH; SEQ ID NO: 45 Ac-Nle-c(Cys-His-D-Phe-Arg-D-Trp-Ahx-Cys)-OH; SEQ ID NO: 45 Ac-Nle-c(Cys-His-D-Phe-Arg-D-Trp-β-Ala-Cys)-OH; SEQ ID NO: 45 Ac-Nle-c(Cys-His-D-Phe-Arg-D-Trp-D-Ala-Cys)-OH; SEQ ID NO: 46 Ac-Nle-c(Cys-D-Ala-His-D-2-Nal-Arg-Trp-Cys)-OH; SEQ ID NO: 46 Ac-Nle-c(Cys-D-Ala-His-D-2-Nal-Arg-2-Nal-Cys)-OH; SEQ ID NO: 46 Ac-Nle-c(Cys-D-Ala-His-D-2-Nal-Arg-1-Nal-Cys)-OH; SEQ ID NO: 46 Ac-Nle-c(Cys-D-Ala-His-D-2-Nal-Arg-Bal-Cys)-OH; SEQ ID NO: 47 Ac-Nle-c(Pen-D-Ala-His-D-Phe-Arg-Trp-Cys)-OH; SEQ ID NO: 29 Ac-Nle-c(Cys-D-Ala-His-D-Phe-Arg-Trp-Pen)-OH; SEQ ID NO: 48 Ac-Nle-c(Cys-His-D-Phe-Arg-Trp-Gaba-Pen)-OH; SEQ ID NO: 49 Ac-Arg-c(Cys-D-Ala-His-D-2-Nal-Arg-Trp-Cys)-NH₂; SEQ ID NO: 50 Ac-Arg-c(Cys-D-Ala-His-D-Phe-Arg-Trp-Cys)-NH₂; SEQ ID NO: 50 Ac-D-Arg-c(Cys-D-Ala-His-D-Phe-Arg-Trp-Cys)-NH₂; SEQ ID NO: 51 Ac-D-Arg-c(Cys-D-Ala-His-D-Phe-Arg-Trp-Pen)-NH₂; SEQ ID NO: 52 Ac-D-Arg-c(Cys-His-D-Phe-Arg-Trp-Gaba-Pen)-NH₂; SEQ ID NO: 52 Ac-Arg-c(Cys-His-D-Phe-Arg-Trp-Gaba-Pen)-NH₂; SEQ ID NO: 51 Ac-Arg-c(Cys-D-Ala-His-D-Phe-Arg-Trp-Pen)-NH₂; SEQ ID NO: 53 Ac-D-Arg-c(Asp-His-D-Phe-Arg-Trp-Ala-Lys)-NH₂; SEQ ID NO: 53 Ac-Arg-c(Asp-His-D-Phe-Arg-Trp-Ala-Lys)-NH₂; SEQ ID NO: 7 Ac-Nle-c(Cys-D-Ala-His-D-Phe-Arg-Trp-Cys)-NH₂; SEQ ID NO: 24 D-Phe-c(Cys-His-D-(Et)Tyr-Arg-Trp-β-Ala-D-Cys)-Thr-NH₂; SEQ ID NO: 27 Nle-c(Cys-His-D-Phe-Arg-Trp-Apn-Cys)-NH₂; SEQ ID NO: 32 Ac-Nle-c(Cys-His-D-Phe-Arg-Trp-Gaba-Pen)-NH₂; SEQ ID NO: 34 Nle-c(Cys-His-D-Phe-Arg-Trp-Gaba-Cys)-NH₂; SEQ ID NO: 1 Ac-Nle-c(Asp-His-D-Phe-Arg-Trp-β-Ala-Lys)-NH₂; SEQ ID NO: 2 Ac-Nle-c(Cys-His-D-Phe-Arg-Trp-Ahx-Cys)-NH₂; SEQ ID NO: 3 D-Phe-c(Cys-His-D-Phe-Arg-Trp-β-Ala-D-Cys)-Thr-NH₂; SEQ ID NO: 3 D-Phe-c(Cys-His-D-Phe-Arg-Trp-Gaba-D-Cys)-Thr-NH₂; SEQ ID NO: 2 Ac-Nle-c(Cys-His-D-Phe-Arg-Trp-Apn-Cys)-NH₂; SEQ ID NO: 4 Ac-Nle-c(Asp-His-D-Phe-Arg-Trp-Apn-Lys)-NH₂; SEQ ID NO: 6 Ac-Cha-c(Asp-His-D-Phe-Arg-Trp-Gaba-Lys)-NH₂; SEQ ID NO: 6 Ac-Nle-c(Asp-His-D-Phe-Arg-Trp-Gaba-Lys)-NH₂; SEQ ID NO: 11 Ac-Chg-c(Asp-His-D-Phe-Arg-Trp-Gaba-Lys)-NH₂; SEQ ID NO: 11 Ac-hCha-c(Asp-His-D-Phe-Arg-Trp-Gaba-Lys)-NH₂; SEQ ID NO: 11 Ac-D-Chg-c(Asp-His-D-Phe-Arg-Trp-Gaba-Lys)-NH₂; SEQ ID NO: 11 Ac-hPhe-c(Asp-His-D-Phe-Arg-Trp-Gaba-Lys)-NH₂; SEQ ID NO: 15 Ac-Nle-c(Cys-His-D-Phe-Arg-D-Trp-β-Ala-Cys)-NH₂; SEQ ID NO: 21 Ac-Nle-c(Pen-D-Ala-His-D-Phe-Arg-Trp-Cys)-NH₂; SEQ ID NO: 22 Ac-Nle-c(Cys-D-Ala-His-D-Phe-Arg-Trp-Pen)-NH₂; SEQ ID NO: 23 D-Phe-c(Cys-His-D-Phe-hArg-Trp-β-Ala-D-Cys)-Thr-NH₂; SEQ ID NO: 25 D-Phe-c(Cys-His-D-Phe-Arg-Bip-β-Ala-D-Cys)-Thr-NH₂; SEQ ID NO: 24 D-Phe-c(Cys-His-D-(Et)Tyr-hArg-Trp-β-Ala-D-Cys)-Thr-NH₂; SEQ ID NO: 26 D-Phe-c(Cys-His-D-Phe-hArg-Bip-β-Ala-D-Cys)-Thr-NH₂; SEQ ID NO: 26 D-Phe-c(Cys-His-D-(Et)Tyr-hArg-Bip-β-Ala-D-Cys)-Thr-NH₂; SEQ ID NO: 28 Ac-Nle-c(Asp-D-Ala-His-D-Phe-Arg-Trp-Lys)-NH₂; SEQ ID NO: 28 Ac-Nle-c(Asp-D-Ala-His-D-Phe-Arg-Bal-Lys)-NH₂; SEQ ID NO: 29 Ac-Nle-c(Cys-D-Ala-His-D-Phe-Arg-Trp-Pen)-OH; SEQ ID NO: 30 Ac-Nle-c(Cys-D-Abu-His-D-Phe-Arg-Trp-Cys)-NH₂; SEQ ID NO: 30 Ac-Nle-c(Cys-D-Val-His-D-Phe-Arg-Trp-Cys)-NH₂; SEQ ID NO: 30 Ac-Nle-c(Cys-D-Ile-His-D-Phe-Arg-Trp-Cys)-NH₂; SEQ ID NO: 30 Ac-Nle-c(Cys-D-Leu-His-D-Phe-Arg-Trp-Cys)-NH₂; SEQ ID NO: 30 Ac-Nle-c(Cys-D-Tle-His-D-Phe-Arg-Trp-Cys)-NH₂; SEQ ID NO: 30 Ac-Nle-c(Cys-D-Cha-His-D-Phe-Arg-Trp-Cys)-NH₂; SEQ ID NO: 31 Ac-Nle-c(Pen-His-D-Phe-Arg-Trp-Gaba-Cys)-NH₂; SEQ ID NO: 32 Ac-Nle-c(Pen-His-D-Phe-Arg-Trp-Gaba-Pen)-NH₂; SEQ ID NO: 33 Ac-Leu-c(Cys-His-D-Phe-Arg-Trp-Gaba-Cys)-NH₂; SEQ ID NO: 33 Ac-Cha-c(Cys-His-D-Phe-Arg-Trp-Gaba-Cys)-NH₂; SEQ ID NO: 33 Ac-Ile-c(Cys-His-D-Phe-Arg-Trp-Gaba-Cys)-NH₂; SEQ ID NO: 33 Ac-Phe-c(Cys-His-D-Phe-Arg-Trp-Gaba-Cys)-NH₂; SEQ ID NO: 33 Ac-Val-c(Cys-His-D-Phe-Arg-Trp-Gaba-Cys)-NH₂; SEQ ID NO: 33 Ac-2-Nal-c(Cys-His-D-Phe-Arg-Trp-Gaba-Cys)-NH₂; SEQ ID NO: 34 Phe-c(Cys-His-D-Phe-Arg-Trp-Gaba-Cys)-NH₂; SEQ ID NO: 35 Ac-Nle-c(Cys-3-Pal-D-Phe-Arg-Trp-Gaba-Cys)-NH₂; SEQ ID NO: 36 Ac-Nle-c(Cys-D-Ala-His-D-Phe-Arg-Trp-Cys)-OH; SEQ ID NO: 37 Ac-Nle-c(Cys-His-Phe-Arg-D-Trp-Gaba-Cys)-NH₂; SEQ ID NO: 16 Ac-Nle-c(Cys-D-Ala-His-D-2-Nal-Arg-Trp-Cys)-NH₂; SEQ ID NO: 16 Ac-Nle-c(Cys-D-Ala-His-D-2-Nal-Arg-2-Nal-Cys)-NH₂; SEQ ID NO: 20 Ac-Nle-c(Cys-D-Ala-His-D-2-Nal-Arg-Bal-Cys)-NH₂; SEQ ID NO: 38 Ac-Nle-c(Asp-His-D-2-Nal-Arg-Trp-Ala-Lys)-NH₂; SEQ ID NO: 38 Ac-Nle-c(Asp-His-D-2-Nal-Arg-Trp-β-Ala-Lys)-NH₂; SEQ ID NO: 39 Ac-Nle-c(Cys-His-D-2-Nal-Arg-Trp-Gaba-Cys)-NH₂; SEQ ID NO: 39 Ac-Nle-c(Cys-His-D-2-Nal-Arg-Trp-Ahx-Cys)-NH₂; SEQ ID NO: 40 Ac-hPhe-c(Asp-His-D-2-Nal-Arg-Trp-Gaba-Lys)-NH₂; SEQ ID NO: 40 Ac-Cha-c(Asp-His-D-2-Nal-Arg-Trp-Gaba-Lys)-NH₂; or SEQ ID NO: 49 Ac-Arg-c(Cys-D-Ala-His-D-2-Nal-Arg-Trp-Cys)-NH₂; or pharmaceutically acceptable salts thereof.

In the second embodiment, the invention provides a method to treat insulin resistance in a mammalian subject, with or without weight loss, by the administration of a therapeutically effective amount of a melanocortin receptor ligand according to Formula (II) and pharmaceutically acceptable salts, hydrates, solvates or prodrugs thereof (see International Patent Application Publication Number WO 2007/008704 incorporated herein by reference in its entirety):

(R²R³)-A¹-c(A²-A³-A⁴-A⁵-A⁶-A⁷-A⁸-A⁹)-NH₂   (II)

wherein:

A¹ is Nle or deleted;

A² is Cys or Asp;

A³ is Glu or D-Ala;

A⁴ is His;

A⁵ is D-Phe;

A⁶ is Arg;

A⁷ is Trp, 2-Nal or Bal;

A⁸ is Gly, Ala, D-Ala, β-Ala, Gaba or Apn;

A⁹ is Cys or Lys;

each of R² and R³ is independently selected from the group consisting of H or (C₁-C₆)acyl;

provided that

-   -   (I). when R² is (C₁-C₆)acyl, then R³ is H; and     -   (II). when A² is Cys, then A⁹ is Cys,         or a pharmaceutically acceptable salt thereof.

More preferred of the immediately foregoing group of compounds which are useful to treat insulin resistance in a mammalian subject, with or without weight loss, are compounds of the formula:

SEQ ID NO: 54 Ac-Nle-c(Cys-D-Ala-His-D-Phe-Arg-Trp-Gly-Cys)-NH₂; SEQ ID NO: 54 Ac-Nle-c(Cys-D-Ala-His-D-Phe-Arg-Trp-D-Ala-Cys)- NH₂; SEQ ID NO: 54 Ac-Nle-c(Cys-D-Ala-His-D-Phe-Arg-Trp-β-Ala-Cys)- NH₂; SEQ ID NO: 54 Ac-Nle-c(Cys-D-Ala-His-D-Phe-Arg-Trp-Gaba-Cys)- NH₂; SEQ ID NO: 54 Ac-Nle-c(Cys-D-Ala-His-D-Phe-Arg-Trp-Apn-Cys)-NH₂; SEQ ID NO: 55 Ac-c(Cys-Glu-His-D-Phe-Arg-Trp-Ala-Cys)-NH₂; SEQ ID NO: 55 Ac-c(Cys-Glu-His-D-Phe-Arg-2-Nal-Ala-Cys)-NH₂; SEQ ID NO: 56 Ac-c(Cys-D-Ala-His-D-Phe-Arg-Trp-Ala-Cys)-NH₂; SEQ ID NO: 56 Ac-c(Cys-D-Ala-His-D-Phe-Arg-2-Nal-Ala-Cys)-NH₂; SEQ ID NO: 57 Ac-Nle-c(Cys-D-Ala-His-D-Phe-Arg-Trp-Ala-Cys)-NH₂; SEQ ID NO: 57 Ac-Nle-c(Cys-D-Ala-His-D-Phe-Arg-Trp-β-Ala-Cys)- NH₂; SEQ ID NO: 57 Ac-Nle-c(Cys-D-Ala-His-D-Phe-Arg-Trp-Gaba-Cys)- NH₂; or SEQ ID NO: 58 Ac-Nle-c(Asp-D-Ala-His-D-Phe-Arg-Bal-Ala-Lys)-NH₂; or a pharmaceutically acceptable salt thereof.

In the third embodiment, the invention provides a method to treat insulin resistance in a mammalian subject, with or without weight loss, by the administration of a therapeutically effective amount of a melanocortin receptor compound according to Formula (III), and pharmaceutically acceptable salts, hydrates, solvates or prodrugs thereof (see International Application Publication Number WO 2007/008684, incorporated herein by reference in its entirety):

(R²R³)—B¹-A¹-c(A²-A³-A⁴-A⁵-A⁶-A⁷-A⁸-A⁹)-A¹⁰-A¹¹-A¹²-A¹³-B²—B³—R¹   (III)

wherein:

B¹ is a peptide moiety which contains 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, or 15 amino acids, wherein at least 5 amino acids are independently selected from the group consisting of L-Arg, D-Arg, L-hArg and D-hArg, or B¹ is optionally deleted;

A¹ is Acc, HN—(CH₂)_(m)—(C(O), L- or D-amino acid or deleted;

A² is Cys, D-Cys, hCys, D-hCys, Pen, D-Pen, Asp or Glu;

A³ is Gly, Glu, Ala, β-Ala, Gaba, Aib, D-amino acid or deleted;

A⁴ is His, 2-Pal, 3-Pal, 4-Pal, Taz, 2-Thi, 3-Thi or (X¹,X²,X³,X⁴,X⁵)Phe;

A⁵ is D-Phe, D-1-Nal, D-2-Nal, D-Trp, D-Bal, D-(X¹,X²,X³,X⁴,X⁵)Phe, D-(Et)Tyr, D-Dip, D-Bip or D-Bpa;

A⁶ is Arg, hArg, Dab, Dap, Lys, Orn or HN—CH((CH₂)_(n)—N(R⁴R⁵))—(C(O);

A⁷ is Trp, 1-Nal, 2-Nal, Bal, Bip, Dip, Bpa, D-Trp, D-1-Nal, D-2-Nal, D-Bal, D-Bip, D-Dip or D-Bpa;

A⁸ is Gly, D-Ala, Acc, Ala, β-Ala, Gaba, Apn, Ahx, Aha, HN—(CH₂)_(s)—(C(O) or deleted;

A⁹ is Cys, D-Cys, hCys, D-hCys, Pen, D-Pen, Dab, Dap, Orn or Lys;

A¹⁰ is Acc, HN—(CH₂)_(t)—(C(O), Pro, hPro, 3-Hyp, 4-Hyp, Thr, an L- or D-amino acid or deleted;

A¹¹ is Pro, hPro, 3-Hyp, 4-Hyp or deleted;

A¹² is Lys, Dab, Dap, Arg, hArg or deleted;

A¹³ is Asp, Glu or deleted;

B² is a peptide moiety containing 1, 2, 3, 4, or 5 amino acids or deleted,

B³ is a peptide moiety which contains 5, 6, 7, 8, 9, 10, 11, 12, 13, 14 or 15 amino acids wherein at least 5 amino acids are independently selected from the group consisting of L-Arg, D-Arg, L-hArg and D-hArg, or is deleted;

R¹ is OH or NH₂;

R² and R³ each is, independently for each occurrence, selected from the group consisting of H, (C₁-C₃₀)alkyl, (C₁-C₃₀)heteroalkyl, (C₁-C₃₀)acyl, (C₂-C₃₀)alkenyl, (C₂-C₃₀)alkynyl, aryl(C₁-C₃₀)alkyl, aryl(C₁-C₃₀)acyl, substituted (C₁-C₃₀)alkyl, substituted (C₁-C₃₀)heteroalkyl, substituted (C₁-C₃₀)acyl, substituted (C₂-C₃₀)alkenyl, substituted (C₂-C₃₀)alkynyl, substituted aryl(C₁-C₃₀)alkyl and substituted aryl(C₁-C₃₀)acyl;

R⁴ and R⁵ each is, independently for each occurrence, H, (C₁-C₄₀)alkyl, (C₁-C₄₀)heteroalkyl, (C₁-C₄₀)acyl, (C₂-C₄₀)alkenyl, (C₂-C₄₀)alkynyl, aryl(C₁-C₄₀)alkyl, aryl(C₁-C₄₀)acyl, substituted (C₁-C₄₀)alkyl, substituted (C₁-C₄₀)heteroalkyl, substituted (C₁-C₄₀)acyl, substituted (C₂-C₄₀)alkenyl, substituted (C₂-C₄₀)alkynyl, substituted aryl(C₁-C₄₀)alkyl, substituted aryl(C₁-C₄₀)acyl, (C₁-C₄₀)alkylsulfonyl or C(NH)—NH₂;

n is, independently for each occurrence, 1, 2, 3, 4 or 5;

m is, independently for each occurrence, 1, 2, 3, 4, 5, 6 or 7;

s is, independently for each occurrence, 1, 2, 3, 4, 5, 6 or 7;

t is, independently for each occurrence, 1, 2, 3, 4, 5, 6 or 7;

X¹, X², X³, X⁴ and X⁵ each is, independently for each occurrence, H, F, Cl, Br, I, (C₁₋₁₀)alkyl, substituted (C₁₋₁₀)alkyl, (C₂₋₁₀)alkenyl, substituted (C₂₋₁₀)alkenyl, (C₂₋₁₀)alkynyl, substituted (C₂₋₁₀)alkynyl, aryl, substituted aryl, OH, NH₂, NO₂ or CN;

provided that:

(I) when R⁴ is (C₁-C₄₀)acyl, aryl(C₁-C₄₀)acyl, substituted (C₁-C₄₀)acyl, substituted aryl(C₁-C₄₀)acyl, (C₁-C₄₀)alkylsulfonyl or C(NH)—NH₂, then R⁵ is H, (C₁-C₄₀)alkyl, (C₁-C₄₀)heteroalkyl, (C₂-C₄₀)alkenyl, (C₂-C₄₀)alkynyl, aryl(C₁-C₄₀)alkyl, substituted (C₁-C₄₀)alkyl, substituted (C₁-C₄₀)heteroalkyl, substituted (C₂-C₄₀)alkenyl, substituted (C₂-C₄₀)alkynyl or substituted aryl(C₁-C₄₀)alkyl;

(II) when R² is (C₁-C₃₀)acyl, aryl(C₁-C₃₀)acyl, substituted (C₁-C₃₀)acyl or substituted aryl(C₁-C₃₀)acyl, then R³ is H, (C₁-C₃₀)alkyl, (C₁-C₃₀)heteroalkyl, (C₂-C₃₀)alkenyl, (C₂-C₃₀)alkynyl, aryl(C₁-C₃₀)alkyl, substituted (C₁-C₃₀)alkyl, substituted (C₁-C₃₀)heteroalkyl, substituted (C₂-C₃₀)alkenyl, substituted (C₂-C₃₀)alkynyl or substituted aryl(C₁-C₃₀)alkyl;

(III) neither B¹ nor B² contains one or more of the following amino acid sequences: Arg-(Lys)₂-(Arg)₂-Gln-(Arg)₃, Tyr-Ala-Arg-Lys-Ala-(Arg)₂-Gln-Ala-(Arg)₂, Tyr-Ala-Arg-(Ala)₂-(Arg)₂-(Ala)₂-(Arg)₂, Tyr-Ala-(Arg)₉, Tyr-(Ala)₃-(Arg)₇, Tyr-Ala-Arg-Ala-Pro-(Arg)₂-Ala-(Arg)₃ or Tyr-Ala-Arg-Ala-Pro-(Arg)₂-Pro-(Arg)₂;

(IV) either B¹ or B² or both must be present in said compound;

(V) when A² is Cys, D-Cys, hCys, D-hCys, Pen or D-Pen, then A⁹ is Cys, D-Cys, hCys, D-hCys, Pen or D-Pen; and

(VI) when A² is Asp or Glu, then A⁹ is Dab, Dap, Orn or Lys;

or pharmaceutically acceptable salts thereof.

In one aspect of the third embodiment, the invention is directed to the use of compounds of Formula (III) to treat insulin resistance in a mammalian subject, with or without weight loss, wherein

B¹ is Arg-Lys-Gln-Lys-(Arg)₅, Arg-(Lys)₂-Arg-Gln-(Arg)₄, Arg-(Lys)₂-(Arg)₃-Gln-(Arg)₂, Arg-(Lys)₂-(Arg)₄-Gln-Arg, Arg-(Lys)₂-(Arg)₅-Gln, Arg-(Lys)₂-Gln-(Arg)₅, Arg-Gln-(Lys)₂-(Arg)₅, Arg-Gln-(Arg)₇, Arg-Gln-(Arg)₈, (Arg)₂-Gln-(Arg)₆, (Arg)₂-Gln-(Arg)₇, (Arg)₃-Gln-(Arg)₅, (Arg)₃-Gln-(Arg)₆, (Arg)₄-Gln-(Arg)₄, (Arg)₄-Gln-(Arg)₅, (Arg)₅, (Arg)₅-Gln-(Arg)₃, (Arg)₅-Gln-(Arg)₄, (Arg)₆, (Arg)₆-Gln-(Arg)₃, (Arg)₇, (Arg)₇-Gln-(Arg)₂, (Arg)₈, (Arg)₈-Gln-Arg, (Arg)₉, (Arg)₉-Gln, (D-Arg)₅, (D-Arg)₆, (D-Arg)₇, (D-Arg)₈, (D-Arg)₉, Gln-Arg-(Lys)₂-(Arg)₅, Gln-(Arg)₈, Gln-(Arg)₉, Tyr-Gly-Arg-(Lys)₂-(Arg)₂-Gln-(Arg)₃, Tyr-Gly-Arg-(Lys)₂-(Arg)₂-Gln-(Arg)₃-Doc; or deleted;

B² is β-Ala, β-Ala-Gly, β-Ala-Tyr, β-Ala-Tyr-Gly, (β-Ala)₂, (β-Ala)₂-Gly, (β-Ala)₂-Tyr, (β-Ala)₂-Tyr-Gly, Doc, Doc-Gly, Doc-Tyr, Doc-Tyr-Gly, (Doc)₂, (Doc)₂-Gly, (Doc)₂-Tyr, Doc)₂-Tyr-Gly, or deleted;

B³ is Arg-Lys-Gln-Lys-(Arg)₅, Arg-Lys-(Arg)₃-Gln-(Arg)₃, Arg-(Lys)₂-Arg-Gln-(Arg)₄, Arg-(Lys)₂-Gln-(Arg)₅, Arg-(Lys)₂-(Arg)₂-Gln-(Arg)₃, Arg-(Lys)₂-(Arg)₃-Gln-(Arg)₂, Arg-(Lys)₂-(Arg)₄-Gln-Arg, Arg-(Lys)₂-(Arg)₅-Gln, Arg-Gln-(Lys)₂-(Arg)₅, Arg-Gln-(Arg)₇, Arg-Gln-(Arg)₈, (Arg)₂-Lys-(Arg)₂-Gln-(Arg)₃, (Arg)₂-Gln-(Arg)₆, (Arg)₂-Gln-(Arg)₇, (Arg)₃-Gln-(Arg)₅, (Arg)₃-Gln-(Arg)₆, (Arg)₄-Gln-(Arg)₄, (Arg)₄-Gln-(Arg)₅, (Arg)₅, (Arg)₅-Gln-(Arg)₃, (Arg)₅-Gln-(Arg)₄, (Arg)₆, (Arg)₆-Gln-(Arg)₃, (Arg)₇, (Arg)₇-Gln-(Arg)₂, (Arg)₈, (Arg)₈-Gln-Arg, (Arg)₉, (Arg)₉-Gln, (D-Arg)₅, (D-Arg)₆, (D-Arg)₇, (D-Arg)₈, (D-Arg)₉, Gln-Arg-(Lys)₂-(Arg)₅, Gln-(Arg)₈, Gln-(Arg)₉, or deleted;

A¹ is A6c, Cha, hCha, Chg, D-Chg, hChg, Gaba, hLeu, Met, β-hMet, D-2-Nal, Nip, Nle, Oic, Phe, D-Phe, hPhe, hPro, or deleted;

A² is Cys

A³ is D-Abu, Aib, Ala, β-Ala, D-Ala, D-Cha, Gaba, Glu, Gly, D-Ile, D-Leu, D-Met, D-Nle, D-Phe, D-Tle, D-Trp, D-Tyr, D-Val, or deleted;

A⁴ is His;

A⁵ is D-Bal, D-1-Nal, D-2-Nal, D-Phe, D-(X¹,X²,X³,X⁴,X⁵)Phe, D-Trp, or D-(Et)Tyr;

A⁶ is Arg or hArg;

A⁷ is Bal, Bip, 1-Nal, 2-Nal, Trp, or D-Trp;

A⁸ is A⁵c, A⁶c, Aha, Ahx, Ala, β-Ala, Apn, Gaba, Gly, or deleted;

A⁹ is Cys, D-Cys, hCys, D-hCys, Lys, Pen, or D-Pen;

A¹⁰ is Pro, Thr or deleted;

A¹¹ is Pro or deleted;

A¹² is arg, Lys, or deleted;

A¹³ is Asp or deleted;

-   -   each of R² and R³ is, independently, H or acyl;         or pharmaceutically acceptable salts thereof.

Preferred ligands of the immediately foregoing group of compounds according to Formula (III), useful to treat insulin resistance in a mammalian subject, with or without weight loss, are compounds of the formula:

(SEQ ID NO: 60) Tyr-Gly-Arg-(Lys)₂-(Arg)₂-Gln-(Arg)₃-Nle-c(Asp-His-D-2-Nal-Arg-Trp-Lys)-NH₂; (SEQ ID NO: 61) Tyr-Gly-Arg-(Lys)₂-(Arg)₂-Gln-(Arg)₃-Doc-Nle-c(Asp-His-D-2-Nal-Arg-Trp-Lys)- NH₂; (SEQ ID NO: 62) Nle-c(Asp-His-D-2-Nal-Arg-Trp-Lys)-β-Ala-Tyr-Gly-Arg-(Lys)₂-(Arg)₂-Gln-(Arg)₃- NH₂; (SEQ ID NO: 62) Ac-Nle-c(Asp-His-D-2-Nal-Arg-Trp-Lys)-β-Ala-Tyr-Gly-Arg-(Lys)₂-(Arg)₂-Gln- (Arg)₃-NH₂; (SEQ ID NO: 63) Nle-c(Asp-His-D-2-Nal-Arg-Trp-Lys)-(Doc)₂-Tyr-Gly-Arg-(Lys)₂-(Arg)₂-Gln-(Arg)₃- NH₂; (SEQ ID NO: 64) Ac-Nle-c(Asp-His-D-2-Nal-Arg-Trp-Lys)-(Pro)₂-Lys-Asp-Tyr-Gly-Arg-(Lys)₂-(Arg)₂- Gln-(Arg)₃-NH₂; (SEQ ID NO: 65) Ac-c(Cys-Glu-His-D-2-Nal-Arg-Trp-Gly-Cys)-(Pro)₂-Lys-Asp-Tyr-Gly-Arg-(Lys)₂- (Arg)₂-Gln-(Arg)₃-NH₂; (SEQ ID NO: 66) Ac-Nle-c(Asp-His-D-2-Nal-Arg-Trp-Lys)-(β-Ala)₂-Tyr-Gly-Arg-(Lys)₂-(Arg)₂-Gln- (Arg)₃-NH₂; (SEQ ID NO: 67) Ac-Nle-c(Asp-His-D-2-Nal-Arg-Trp-Lys)-(Pro)₂-Lys-Asp-Doc-Tyr-Gly-Arg-(Lys)₂- (Arg)₂-Gln-(Arg)₃-NH₂; (SEQ ID NO: 68) Ac-c(Cys-Glu-His-D-2-Nal-Arg-Trp-Gly-Cys)-(Pro)₂-Lys-Asp-Doc-Tyr-Gly-Arg- (Lys)₂-(Arg)₂-Gln-(Arg)₃-NH₂; (SEQ ID NO: 69) Ac-c(Cys-Glu-His-D-2-Nal-Arg-Trp-Ala-Cys)-(Pro)₂-Lys-Asp-β-Ala-Tyr-Gly-Arg- (Lys)₂-(Arg)₂-Gln-(Arg)₃-NH₂; (SEQ ID NO: 69) Ac-c(Cys-Glu-His-D-2-Nal-Arg-Trp-Ala-Cys)-(Pro)₂-Lys-Asp-Doc-Tyr-Gly-Arg- (Lys)₂-(Arg)₂-Gln-(Arg)₃-NH₂; (SEQ ID NO: 70) Ac-Nle-c(Asp-His-D-2-Nal-Arg-Trp-Lys)-(Doc)₂-Tyr-Gly-Arg-(Lys)₂-(Arg)₂-Gln- (Arg)₃-NH₂; (SEQ ID NO: 71) Ac-c(Cys-Glu-His-D-2-Nal-Arg-2-Nal-Ala-Cys)-(Pro)₂-Lys-Asp-β-Ala-Tyr-Gly-Arg- (Lys)₂-(Arg)₂-Gln-(Arg)₃-NH₂; (SEQ ID NO: 72) Ac-c(Cys-Glu-His-D-2-Nal-Arg-Bal-Ala-Cys)-(Pro)₂-Lys-Asp-β-Ala-(Arg)₅-Gln- (Arg)₃-NH₂; (SEQ ID NO: 73) Ac-c(Cys-Glu-His-D-2-Nal-Arg-Bal-Ala-Cys)-(Pro)₂-Lys-Asp-β-Ala-Gly-(Arg)₅-Gln- (Arg)₃-NH₂; (SEQ ID NO: 74) Ac-c(Cys-Glu-His-D-2-Nal-Arg-Bal-Ala-Cys)-(Pro)₂-Lys-Asp-β-Ala-Tyr-Gly-(Arg)₅- Gln-(Arg)₃-NH₂; (SEQ ID NO: 75) Ac-c(Cys-Glu-His-D-2-Nal-Arg-Trp-Ala-Cys)-(Pro)₂-Lys-Asp-β-Ala-Tyr-Gly-Arg- (Lys)₂-Arg-Gln-(Arg)₄-NH₂; (SEQ ID NO: 76) Ac-c(Cys-Glu-His-D-2-Nal-Arg-Trp-Ala-Cys)-(Pro)₂-Lys-Asp-β-Ala-Tyr-Gly-Arg- (Lys)₂-Gln-(Arg)₅-NH₂; (SEQ ID NO: 77) Ac-c(Cys-Glu-His-D-2-Nal-Arg-Trp-Ala-Cys)-(Pro)₂-Lys-Asp-β-Ala-Tyr-Gly-Arg- Lys-Gln-Lys-(Arg)₅-NH₂; (SEQ ID NO: 78) Ac-c(Cys-Glu-His-D-2-Nal-Arg-Trp-Ala-Cys)-(Pro)₂-Lys-Asp-β-Ala-Tyr-Gly-Arg- (Lys)₂-(Arg)₄-Gln-Arg-NH₂; (SEQ ID NO: 79) Ac-c(Cys-Glu-His-D-2-Nal-Arg-Bal-Ala-Cys)-(Pro)₂-Lys-Asp-β-Ala-Tyr-Aib-Arg- (Lys)₂-(Arg)₂-Gln-(Arg)₃-NH₂; (SEQ ID NO: 80) Ac-c(Cys-Glu-His-D-2-Nal-Arg-1-Nal-Ala-Cys)-(Pro)₂-Arg-Asp-β-Ala-(Arg)₅-Gln- (Arg)₃-NH₂; (SEQ ID NO: 80) Ac-c(Cys-Glu-His-D-2-Nal-Arg-1-Nal-Ala-Cys)-(Pro)₂-Lys-Asp-β-Ala-(Arg)₅-Gln- (Arg)₃-NH₂; (SEQ ID NO: 81) Ac-c(Cys-Glu-His-D-2-Nal-Arg-1-Nal-Ala-Cys)-(Pro)₂-Lys-Asp-β-Ala-(Arg)₆-Gln- (Arg)₃-NH₂; (SEQ ID NO: 82) Ac-c(Cys-Glu-His-D-2-Nal-Arg-2-Nal-Ala-Cys)-(Pro)₂-Arg-Asp-β-Ala-(Arg)₅-Gln- (Arg)₃-NH₂; (SEQ ID NO: 82) Ac-c(Cys-Glu-His-D-2-Nal-Arg-2-Nal-Ala-Cys)-(Pro)₂-Lys-Asp-β-Ala-(Arg)₅-Gln- (Arg)₃-NH₂; (SEQ ID NO: 81) Ac-c(Cys-Glu-His-D-2-Nal-Arg-2-Nal-Ala-Cys)-(Pro)₂-Lys-Asp-β-Ala-(Arg)₆-Gln- (Arg)₃-NH₂; (SEQ ID NO: 83) Ac-c(Cys-Glu-His-D-2-Nal-Arg-Bal-Ala-Cys)-(Pro)₂-Arg-Asp-β-Ala-(Arg)₆-Gln- (Arg)₃-NH₂; (SEQ ID NO: 84) Ac-c(Cys-Glu-His-D-2-Nal-Arg-Bal-Ala-Cys)-(Pro)₂-Arg-Asp-β-Ala-(Arg)₅-Gln- (Arg)₃-NH₂; (SEQ ID NO: 83) Ac-c(Cys-Glu-His-D-2-Nal-Arg-Bal-Ala-Cys)-(Pro)₂-Lys-Asp-β-Ala-(Arg)₆-Gln- (Arg)₃-NH₂; (SEQ ID NO: 85) Ac-c(Cys-Glu-His-D-2-Nal-Arg-Trp-Ala-Cys)-(Pro)₂-Lys-Asp-β-Ala-Tyr-Gly-Arg- (Lys)₂-(Arg)₃-Gln-(Arg)₂-NH₂; (SEQ ID NO: 86) Ac-c(Cys-Glu-His-D-2-Nal-Arg-Trp-Ala-Cys)-(Pro)₂-Lys-Asp-β-Ala-Tyr-Gly-Arg- Gln-(Lys)₂-(Arg)₅-NH₂; (SEQ ID NO: 87) Ac-c(Cys-Glu-His-D-2-Nal-Arg-Trp-Ala-Cys)-(Pro)₂-Lys-Asp-β-Ala-Tyr-Gly-Arg- (Lys)₂-(Arg)₅-Gln-NH₂; (SEQ ID NO: 71) Ac-c(Cys-Glu-His-D-2-Nal-Arg-1-Nal-Ala-Cys)-(Pro)₂-Lys-Asp-β-Ala-Tyr-Gly-Arg- (Lys)₂-(Arg)₂-Gln-(Arg)₃-NH₂; (SEQ ID NO: 71) Ac-c(Cys-Glu-His-D-2-Nal-Arg-Bal-Ala-Cys)-(Pro)₂-Lys-Asp-β-Ala-Tyr-Gly-Arg- (Lys)₂-(Arg)₂-Gln-(Arg)₃-NH₂; (SEQ ID NO: 88) Ac-c(Cys-Glu-His-D-2-Nal-Arg-1-Nal-Ala-Cys)-(Pro)₂-Lys-Asp-β-Ala-(Arg)₂-Lys- (Arg)₂-Gln-(Arg)₃-NH₂; (SEQ ID NO: 89) Ac-c(Cys-Glu-His-D-2-Nal-Arg-1-Nal-Ala-Cys)-(Pro)₂-Lys-Asp-β-Ala-Arg-Lys- (Arg)₃-Gln-(Arg)₃-NH₂; (SEQ ID NO: 88) Ac-c(Cys-Glu-His-D-2-Nal-Arg-2-Nal-Ala-Cys)-(Pro)₂-Lys-Asp-β-Ala-(Arg)₂-Lys- (Arg)₂-Gln-(Arg)₃-NH₂; (SEQ ID NO: 90) Ac-c(Cys-Glu-His-D-2-Nal-Arg-2-Nal-Ala-Cys)-(Pro)₂-Lys-Asp-β-Ala-Tyr-Gly-(Arg)₂- Lys-(Arg)₂-Gln-(Arg)₃-NH₂; (SEQ ID NO: 91) Ac-c(Cys-Glu-His-D-2-Nal-Arg-2-Nal-Ala-Cys)-(Pro)₂-Lys-Asp-β-Ala-Gly-(Arg)₂-Lys- (Arg)₂-Gln-(Arg)₃-NH₂; (SEQ ID NO: 92) Ac-c(Cys-Glu-His-D-2-Nal-Arg-2-Nal-Ala-Cys)-(Pro)₂-Lys-Asp-β-Ala-Gly-Arg-Lys- (Arg)₃-Gln-(Arg)₃-NH₂; (SEQ ID NO: 93) Ac-c(Cys-Glu-His-D-2-Nal-Arg-1-Nal-Ala-Cys)-(Pro)₂-Lys-Asp-β-Ala-(Arg)₂-Lys- (Arg)₂-Gln-(Arg)₃-NH₂; (SEQ ID NO: 94) Ac-c(Cys-Glu-His-D-2-Nal-Arg-1-Nal-Ala-Cys)-(Pro)₂-Lys-Asp-β-Ala-Arg-Lys- (Arg)₃-Gln-(Arg)₃-NH₂; (SEQ ID NO: 95) Ac-c(Cys-Glu-His-D-2-Nal-Arg-1-Nal-Ala-Cys)-(Pro)₂-Lys-Asp-β-Ala-Tyr-Gly-(Arg)₂- Lys-(Arg)₂-Gln-(Arg)₃-NH₂; (SEQ ID NO: 96) Ac-c(Cys-Glu-His-D-2-Nal-Arg-1-Nal-Ala-Cys)-(Pro)₂-Lys-Asp-β-Ala-Tyr-Gly-Arg- Lys-(Arg)₃-Gln-(Arg)₃-NH₂; (SEQ ID NO: 97) Ac-c(Cys-Glu-His-D-2-Nal-Arg-1-Nal-Ala-Cys)-(Pro)₂-Lys-Asp-β-Ala-Gly-(Arg)₂-Lys- (Arg)₂-Gln-(Arg)₃-NH₂; (SEQ ID NO: 92) Ac-c(Cys-Glu-His-D-2-Nal-Arg-1-Nal-Ala-Cys)-(Pro)₂-Lys-Asp-β-Ala-Gly-Arg-Lys- (Arg)₃-Gln-(Arg)₃-NH₂; (SEQ ID NO: 98) Ac-c(Cys-Glu-His-D-2-Nal-Arg-2-Nal-Ala-Cys)-(Pro)₂-Lys-Asp-β-Ala-(Arg)₂-Lys- (Arg)₂-Gln-(Arg)₃-NH₂; (SEQ ID NO: 99) Ac-c(Cys-Glu-His-D-2-Nal-Arg-2-Nal-Ala-Cys)-(Pro)₂-Lys-Asp-β-Ala-Arg-Lys- (Arg)₃-Gln-(Arg)₃-NH₂; (SEQ ID NO: 100) Ac-c(Cys-Glu-His-D-2-Nal-Arg-2-Nal-Ala-Cys)-(Pro)₂-Lys-Asp-β-Ala-Tyr-Gly-(Arg)₂- Lys-(Arg)₂-Gln-(Arg)₃-NH₂; (SEQ ID NO: 101) Ac-c(Cys-Glu-His-D-2-Nal-Arg-2-Nal-Ala-Cys)-(Pro)₂-Lys-Asp-β-Ala-Tyr-Gly-Arg- Lys-(Arg)₃-Gln-(Arg)₃-NH₂; (SEQ ID NO: 102) Ac-c(Cys-Glu-His-D-2-Nal-Arg-2-Nal-Ala-Cys)-(Pro)₂-Lys-Asp-β-Ala-Gly-(Arg)₂-Lys- (Arg)₂-Gln-(Arg)₃-NH₂; (SEQ ID NO: 103) Ac-c(Cys-Glu-His-D-2-Nal-Arg-2-Nal-Ala-Cys)-(Pro)₂-Lys-Asp-β-Ala-Gly-Arg-Lys- (Arg)₃-Gln-(Arg)₃-NH₂; (SEQ ID NO: 104) Ac-c(Cys-Glu-His-D-2-Nal-Arg-Bal-Ala-Cys)-(Pro)₂-Lys-Asp-β-Ala-(Arg)₂-Lys- (Arg)₂-Gln-(Arg)₃-NH₂; (SEQ ID NO: 105) Ac-c(Cys-Glu-His-D-2-Nal-Arg-Bal-Ala-Cys)-(Pro)₂-Lys-Asp-β-Ala-Arg-Lys-(Arg)₃- Gln-(Arg)₃-NH₂; (SEQ ID NO: 100) Ac-c(Cys-Glu-His-D-2-Nal-Arg-Bal-Ala-Cys)-(Pro)₂-Lys-Asp-β-Ala-Tyr-Gly-(Arg)₂- Lys-(Arg)₂-Gln-(Arg)₃-NH₂; (SEQ ID NO: 101) Ac-c(Cys-Glu-His-D-2-Nal-Arg-Bal-Ala-Cys)-(Pro)₂-Lys-Asp-β-Ala-Tyr-Gly-Arg-Lys- (Arg)₃-Gln-(Arg)₃-NH₂; (SEQ ID NO: 102) Ac-c(Cys-Glu-His-D-2-Nal-Arg-Bal-Ala-Cys)-(Pro)₂-Lys-Asp-β-Ala-Gly-(Arg)₂-Lys- (Arg)₂-Gln-(Arg)₃-NH₂; (SEQ ID NO: 103) Ac-c(Cys-Glu-His-D-2-Nal-Arg-Bal-Ala-Cys)-(Pro)₂-Lys-Asp-β-Ala-Gly-Arg-Lys- (Arg)₃-Gln-(Arg)₃-NH₂; (SEQ ID NO: 106) Ac-c(Cys-Glu-His-D-2-Nal-Arg-Trp-Ala-Cys)-(Pro)₂-Lys-Asp-β-Ala-Tyr-Gly-Arg- (Lys)₂-Arg-Gln-(Arg)₄-NH₂; (SEQ ID NO: 107) Ac-c(Cys-Glu-His-D-2-Nal-Arg-Trp-Ala-Cys)-(Pro)₂-Lys-Asp-β-Ala-Tyr-Gly-Arg- (Lys)₂-Gln-(Arg)₅-NH₂; (SEQ ID NO: 108) Ac-c(Cys-Glu-His-D-2-Nal-Arg-Trp-Ala-Cys)-(Pro)₂-Lys-Asp-β-Ala-Tyr-Gly-Arg- Lys-Gln-Lys-(Arg)₅-NH₂; (SEQ ID NO: 109) Ac-c(Cys-Glu-His-D-2-Nal-Arg-Trp-Ala-Cys)-(Pro)₂-Lys-Asp-β-Ala-Tyr-Gly-Arg- Gln-(Lys)₂-(Arg)₅-NH₂; (SEQ ID NO: 110) Ac-c(Cys-Glu-His-D-2-Nal-Arg-Trp-Ala-Cys)-(Pro)₂-Lys-Asp-β-Ala-Tyr-Gly-Arg- (Lys)₂-(Arg)₃-Gln-(Arg)₂-NH₂; (SEQ ID NO: 111) Ac-c(Cys-Glu-His-D-2-Nal-Arg-Trp-Ala-Cys)-(Pro)₂-Lys-Asp-β-Ala-Tyr-Gly-Arg- (Lys)₂-(Arg)₄-Gln-Arg-NH₂; (SEQ ID NO: 112) Ac-c(Cys-Glu-His-D-2-Nal-Arg-Trp-Ala-Cys)-(Pro)₂-Lys-Asp-β-Ala-Tyr-Gly-Arg- (Lys)₂-(Arg)₅-Gln-NH₂; (SEQ ID NO: 113) Ac-c(Cys-Glu-His-D-2-Nal-Arg-Trp-Ala-Cys)-(Pro)₂-Lys-Asp-β-Ala-(Arg)₅-Gln- (Arg)₃-NH₂; (SEQ ID NO: 113) Ac-c(Cys-Glu-His-D-2-Nal-Arg-Trp-Ala-Cys)-(Pro)₂-Arg-Asp-β-Ala-(Arg)₅-Gln- (Arg)₃-NH₂; (SEQ ID NO: 114) Ac-c(Cys-Glu-His-D-2-Nal-Arg-Trp-Ala-Cys)-(Pro)₂-Lys-Asp-β-Ala-Tyr-Gly-(Arg)₅- Gln-(Arg)₃-NH₂; (SEQ ID NO: 114) Ac-c(Cys-Glu-His-D-2-Nal-Arg-Trp-Ala-Cys)-(Pro)₂-Arg-Asp-β-Ala-Tyr-Gly-(Arg)₅- Gln-(Arg)₃-NH₂; (SEQ ID NO: 115) Ac-c(Cys-Glu-His-D-2-Nal-Arg-Trp-Ala-Cys)-(Pro)₂-Lys-Asp-β-Ala-(Arg)₅-Gln- (Arg)₄-NH₂; (SEQ ID NO: 115) Ac-c(Cys-Glu-His-D-2-Nal-Arg-Trp-Ala-Cys)-(Pro)₂-Arg-Asp-β-Ala-(Arg)₅-Gln- (Arg)₄-NH₂; (SEQ ID NO: 116) Ac-c(Cys-Glu-His-D-2-Nal-Arg-Trp-Ala-Cys)-(Pro)₂-Lys-Asp-β-Ala-Tyr-Gly-(Arg)₅- Gln-(Arg)₄-NH₂; (SEQ ID NO: 116) Ac-c(Cys-Glu-His-D-2-Nal-Arg-Trp-Ala-Cys)-(Pro)₂-Arg-Asp-β-Ala-Tyr-Gly-(Arg)₅- Gln-(Arg)₄-NH₂; (SEQ ID NO: 117) Ac-c(Cys-Glu-His-D-2-Nal-Arg-1-Nal-Ala-Cys)-(Pro)₂-Lys-Asp-β-Ala-(Arg)₅-Gln- (Arg)₃-NH₂; (SEQ ID NO: 117) Ac-c(Cys-Glu-His-D-2-Nal-Arg-1-Nal-Ala-Cys)-(Pro)₂-Arg-Asp-β-Ala-(Arg)₅-Gln- (Arg)₃-NH₂; (SEQ ID NO: 118) Ac-c(Cys-Glu-His-D-2-Nal-Arg-1-Nal-Ala-Cys)-(Pro)₂-Lys-Asp-β-Ala-(Arg)₅-Gln- (Arg)₄-NH₂; (SEQ ID NO: 118) Ac-c(Cys-Glu-His-D-2-Nal-Arg-1-Nal-Ala-Cys)-(Pro)₂-Arg-Asp-β-Ala-(Arg)₅-Gln- (Arg)₄-NH₂; (SEQ ID NO: 119) Ac-c(Cys-Glu-His-D-2-Nal-Arg-1-Nal-Ala-Cys)-(Pro)₂-Lys-Asp-β-Ala-(Arg)₆-Gln- (Arg)₃-NH₂; (SEQ ID NO: 119) Ac-c(Cys-Glu-His-D-2-Nal-Arg-1-Nal-Ala-Cys)-(Pro)₂-Arg-Asp-β-Ala-(Arg)₆-Gln- (Arg)₃-NH₂; (SEQ ID NO: 120) Ac-c(Cys-Glu-His-D-2-Nal-Arg-1-Nal-Ala-Cys)-(Pro)₂-Lys-Asp-β-Ala-Tyr-Gly-(Arg)₅- Gln-(Arg)₃-NH₂; (SEQ ID NO: 120) Ac-c(Cys-Glu-His-D-2-Nal-Arg-1-Nal-Ala-Cys)-(Pro)₂-Arg-Asp-β-Ala-Tyr-Gly- (Arg)₅-Gln-(Arg)₃-NH₂; (SEQ ID NO: 121) Ac-c(Cys-Glu-His-D-2-Nal-Arg-1-Nal-Ala-Cys)-(Pro)₂-Lys-Asp-β-Ala-Tyr-Gly-(Arg)₅- Gln-(Arg)₄-NH₂; (SEQ ID NO: 121) Ac-c(Cys-Glu-His-D-2-Nal-Arg-1-Nal-Ala-Cys)-(Pro)₂-Arg-Asp-β-Ala-Tyr-Gly- (Arg)₅-Gln-(Arg)₄-NH₂; (SEQ ID NO: 122) Ac-c(Cys-Glu-His-D-2-Nal-Arg-1-Nal-Ala-Cys)-(Pro)₂-Lys-Asp-β-Ala-Tyr-Gly-(Arg)₆- Gln-(Arg)₃-NH₂; (SEQ ID NO: 122) Ac-c(Cys-Glu-His-D-2-Nal-Arg-1-Nal-Ala-Cys)-(Pro)₂-Arg-Asp-β-Ala-Tyr-Gly- (Arg)₆-Gln-(Arg)₃-NH₂; (SEQ ID NO: 123) Ac-c(Cys-Glu-His-D-2-Nal-Arg-2-Nal-Ala-Cys)-(Pro)₂-Lys-Asp-β-Ala-(Arg)₅-Gln- (Arg)₃-NH₂; (SEQ ID NO: 123) Ac-c(Cys-Glu-His-D-2-Nal-Arg-2-Nal-Ala-Cys)-(Pro)₂-Arg-Asp-β-Ala-(Arg)₅-Gln- (Arg)₃-NH₂; (SEQ ID NO: 124) Ac-c(Cys-Glu-His-D-2-Nal-Arg-2-Nal-Ala-Cys)-(Pro)₂-Lys-Asp-β-Ala-(Arg)₆-Gln- (Arg)₃-NH₂; (SEQ ID NO: 124) Ac-c(Cys-Glu-His-D-2-Nal-Arg-2-Nal-Ala-Cys)-(Pro)₂-Arg-Asp-β-Ala-(Arg)₆-Gln- (Arg)₃-NH₂; (SEQ ID NO: 125) Ac-c(Cys-Glu-His-D-2-Nal-Arg-2-Nal-Ala-Cys)-(Pro)₂-Lys-Asp-β-Ala-(Arg)₅-Gln- (Arg)₄-NH₂; (SEQ ID NO: 125) Ac-c(Cys-Glu-His-D-2-Nal-Arg-2-Nal-Ala-Cys)-(Pro)₂-Arg-Asp-β-Ala-(Arg)₅-Gln- (Arg)₄-NH₂; (SEQ ID NO: 126) Ac-c(Cys-Glu-His-D-2-Nal-Arg-2-Nal-Ala-Cys)-(Pro)₂-Lys-Asp-β-Ala-Tyr-Gly-(Arg)₅- Gln-(Arg)₃-NH₂; (SEQ ID NO: 126) Ac-c(Cys-Glu-His-D-2-Nal-Arg-2-Nal-Ala-Cys)-(Pro)₂-Arg-Asp-β-Ala-Tyr-Gly- (Arg)₅-Gln-(Arg)₃-NH₂; (SEQ ID NO: 127) Ac-c(Cys-Glu-His-D-2-Nal-Arg-2-Nal-Ala-Cys)-(Pro)₂-Lys-Asp-β-Ala-Tyr-Gly-(Arg)₆- Gln-(Arg)₃-NH₂; (SEQ ID NO: 127) Ac-c(Cys-Glu-His-D-2-Nal-Arg-2-Nal-Ala-Cys)-(Pro)₂-Arg-Asp-β-Ala-Tyr-Gly- (Arg)₆-Gln-(Arg)₃-NH₂; (SEQ ID NO: 128) Ac-c(Cys-Glu-His-D-2-Nal-Arg-2-Nal-Ala-Cys)-(Pro)₂-Lys-Asp-β-Ala-Tyr-Gly-(Arg)₅- Gln-(Arg)₄-NH₂; (SEQ ID NO: 128) Ac-c(Cys-Glu-His-D-2-Nal-Arg-2-Nal-Ala-Cys)-(Pro)₂-Arg-Asp-β-Ala-Tyr-Gly- (Arg)₅-Gln-(Arg)₄-NH₂; (SEQ ID NO: 129) Ac-c(Cys-Glu-His-D-2-Nal-Arg-Bal-Ala-Cys)-(Pro)₂-Lys-Asp-β-Ala-(Arg)₅-Gln- (Arg)₃-NH₂; (SEQ ID NO: 129) Ac-c(Cys-Glu-His-D-2-Nal-Arg-Bal-Ala-Cys)-(Pro)₂-Arg-Asp-β-Ala-(Arg)₅-Gln- (Arg)₃-NH₂; (SEQ ID NO: 130) Ac-c(Cys-Glu-His-D-2-Nal-Arg-Bal-Ala-Cys)-(Pro)₂-Lys-Asp-β-Ala-(Arg)₅-Gln- (Arg)₄-NH₂; (SEQ ID NO: 130) Ac-c(Cys-Glu-His-D-2-Nal-Arg-Bal-Ala-Cys)-(Pro)₂-Arg-Asp-β-Ala-(Arg)₅-Gln- (Arg)₄-NH₂; (SEQ ID NO: 131) Ac-c(Cys-Glu-His-D-2-Nal-Arg-Bal-Ala-Cys)-(Pro)₂-Lys-Asp-β-Ala-(Arg)₆-Gln- (Arg)₃-NH₂; (SEQ ID NO: 131) Ac-c(Cys-Glu-His-D-2-Nal-Arg-Bal-Ala-Cys)-(Pro)₂-Arg-Asp-β-Ala-(Arg)₆-Gln- (Arg)₃-NH₂; (SEQ ID NO: 132) Ac-c(Cys-Glu-His-D-2-Nal-Arg-Bal-Ala-Cys)-(Pro)₂-Lys-Asp-β-Ala-Gly-(Arg)₅-Gln- (Arg)₃-NH₂; (SEQ ID NO: 133) Ac-c(Cys-Glu-His-D-2-Nal-Arg-Bal-Ala-Cys)-(Pro)₂-Lys-Asp-β-Ala-Tyr-Gly-(Arg)₅- Gln-(Arg)₃-NH₂; (SEQ ID NO: 133) Ac-c(Cys-Glu-His-D-2-Nal-Arg-Bal-Ala-Cys)-(Pro)₂-Arg-Asp-β-Ala-Tyr-Gly-(Arg)₅- Gln-(Arg)₃-NH₂; (SEQ ID NO: 134) Ac-c(Cys-Glu-His-D-2-Nal-Arg-Bal-Ala-Cys)-(Pro)₂-Lys-Asp-β-Ala-Tyr-Gly-(Arg)₅- Gln-(Arg)₄-NH₂; (SEQ ID NO: 134) Ac-c(Cys-Glu-His-D-2-Nal-Arg-Bal-Ala-Cys)-(Pro)₂-Arg-Asp-β-Ala-Tyr-Gly-(Arg)₅- Gln-(Arg)₄-NH₂; (SEQ ID NO: 135) Ac-c(Cys-Glu-His-D-2-Nal-Arg-Bal-Ala-Cys)-(Pro)₂-Lys-Asp-β-Ala-Tyr-Gly-(Arg)₆- Gln-(Arg)₃-NH₂; (SEQ ID NO: 135) Ac-c(Cys-Glu-His-D-2-Nal-Arg-Bal-Ala-Cys)-(Pro)₂-Arg-Asp-β-Ala-Tyr-Gly-(Arg)₆- Gln-(Arg)₃-NH₂; (SEQ ID NO: 136) Ac-Nle-c(Cys-D-Ala-His-D-Phe-Arg-Trp-Cys)-(Doc)₂-Tyr-Gly-Arg-(Lys)₂-(Arg)₂-Gln- (Arg)₃-NH₂; (SEQ ID NO: 137) Ac-Nle-c(Cys-D-Ala-His-D-Phe-Arg-Trp-Cys)-β-Ala-Tyr-Gly-Arg-(Lys)₂-Arg-Gln- (Arg)₄-NH₂; (SEQ ID NO: 136) Ac-Nle-c(Cys-D-Ala-His-D-Phe-Arg-Trp-Cys)-Doc-Tyr-Gly-Arg-(Lys)₂-(Arg)₂-Gln- (Arg)₃-NH₂; (SEQ ID NO: 138) Ac-Nle-c(Cys-D-Ala-His-D-Phe-Arg-Trp-Cys)-β-Ala-(Arg)₅-Gln-(Arg)₃-NH₂; (SEQ ID NO: 138) Ac-Nle-c(Cys-D-Ala-His-D-Phe-Arg-Trp-Cys)-β-Ala-Gly-(Arg)₅-Gln-(Arg)₃-NH₂; (SEQ ID NO: 138) Ac-Nle-c(Cys-D-Ala-His-D-Phe-Arg-Trp-Cys)-β-Ala-Gly-(Arg)₅-Gln-(Arg)₃-NH₂; (SEQ ID NO: 139) Ac-Nle-c(Cys-D-Ala-His-D-Phe-Arg-Trp-Cys)-β-Ala-Tyr-Gly-(Arg)₅-Gln-(Arg)₃-NH₂; (SEQ ID NO: 140) Ac-Nle-c(Cys-D-Ala-His-D-Phe-Arg-Trp-Cys)-β-Ala-Gly-(Arg)₅-Gln-(Arg)₄-NH₂; (SEQ ID NO: 141) Ac-Nle-c(Cys-D-Ala-His-D-Phe-Arg-Trp-Cys)-β-Ala-Tyr-Gly-(Arg)₂-Lys-(Arg)₂-Gln- (Arg)₃-NH₂; (SEQ ID NO: 142) Ac-Nle-c(Cys-D-Ala-His-D-Phe-Arg-Trp-Cys)-β-Ala-Tyr-Gly-Arg-Lys-(Arg)₃-Gln- (Arg)₃-NH₂; (SEQ ID NO: 141) Ac-Nle-c(Cys-D-Ala-His-D-Phe-Arg-Trp-Cys)-β-Ala-Gly-(Arg)₂-Lys-(Arg)₂-Gln- (Arg)₃-NH₂; (SEQ ID NO: 142) Ac-Nle-c(Cys-D-Ala-His-D-Phe-Arg-Trp-Cys)-β-Ala-Gly-Arg-Lys-(Arg)₃-Gln-(Arg)₃- NH₂; (SEQ ID NO: 143) Ac-Nle-c(Cys-D-Ala-His-D-Phe-Arg-Trp-Cys)-β-Ala-(Arg)₂-Lys-(Arg)₂-Gln-(Arg)₃- NH₂; (SEQ ID NO: 144) Ac-Nle-c(Cys-D-Ala-His-D-Phe-Arg-Trp-Cys)-β-Ala-Arg-Lys-(Arg)₃-Gln-(Arg)₃-NH₂; (SEQ ID NO: 145) Ac-Nle-c(Cys-D-Ala-His-D-Phe-Arg-Trp-Cys)-β-Ala-Tyr-Gly-Arg-(Lys)₂-Arg-Gln- (Arg)₄-NH₂; (SEQ ID NO: 146) Ac-Nle-c(Cys-D-Ala-His-D-Phe-Arg-Trp-Cys)-Doc-Tyr-Gly-Arg-(Lys)₂-(Arg)₂-Gln- (Arg)₃-NH₂; (SEQ ID NO: 148) Ac-Nle-c(Cys-D-Ala-His-D-Phe-Arg-Trp-Cys)-β-Ala-(Arg)₅-Gln-(Arg)₃-NH₂; (SEQ ID NO: 147) Ac-Nle-c(Cys-D-Ala-His-D-Phe-Arg-Trp-Cys)-β-Ala-Gly-(Arg)₅-Gln-(Arg)₃-NH₂; (SEQ ID NO: 147) Ac-Nle-c(Cys-D-Ala-His-D-Phe-Arg-Trp-Cys)-β-Ala-Tyr-Gly-(Arg)₅-Gln-(Arg)₃-NH₂; (SEQ ID NO: 148) Ac-Nle-c(Cys-D-Ala-His-D-Phe-Arg-Trp-Cys)-(β-Ala)₂-(Arg)₅-Gln-(Arg)₃-NH₂; (SEQ ID NO: 149) Ac-Nle-c(Cys-D-Ala-His-D-Phe-Arg-Trp-Cys)-(β-Ala)₂-Gly-(Arg)₅-Gln-(Arg)₃-NH₂; (SEQ ID NO: 149) Ac-Nle-c(Cys-D-Ala-His-D-Phe-Arg-Trp-Cys)-(β-Ala)₂-Tyr-Gly-(Arg)₅-Gln-(Arg)₃- NH₂; (SEQ ID NO: 151) Ac-Nle-c(Cys-D-Ala-His-D-Phe-Arg-Trp-Cys)-Doc-(Arg)₅-Gln-(Arg)₃-NH₂; (SEQ ID NO: 150) Ac-Nle-c(Cys-D-Ala-His-D-Phe-Arg-Trp-Cys)-Doc-Gly-(Arg)₅-Gln-(Arg)₃-NH₂; (SEQ ID NO: 150) Ac-Nle-c(Cys-D-Ala-His-D-Phe-Arg-Trp-Cys)-Doc-Tyr-Gly-(Arg)₅-Gln-(Arg)₃-NH₂; (SEQ ID NO: 151) Ac-Nle-c(Cys-D-Ala-His-D-Phe-Arg-Trp-Cys)-(Doc)₂-(Arg)₅-Gln-(Arg)₃-NH₂; (SEQ ID NO: 152) Ac-Nle-c(Cys-D-Ala-His-D-Phe-Arg-Trp-Cys)-(Doc)₂-Gly-(Arg)₅-Gln-(Arg)₃-NH₂; (SEQ ID NO: 152) Ac-Nle-c(Cys-D-Ala-His-D-Phe-Arg-Trp-Cys)-(Doc)₂-Tyr-Gly-(Arg)₅-Gln-(Arg)₃-NH₂; (SEQ ID NO: 154) Ac-Nle-c(Cys-D-Ala-His-D-Phe-Arg-Trp-Cys)-β-Ala-(Arg)₅-Gln-(Arg)₄-NH₂; (SEQ ID NO: 153) Ac-Nle-c(Cys-D-Ala-His-D-Phe-Arg-Trp-Cys)-β-Ala-Gly-(Arg)₅-Gln-(Arg)₄-NH₂; (SEQ ID NO: 153) Ac-Nle-c(Cys-D-Ala-His-D-Phe-Arg-Trp-Cys)-β-Ala-Tyr-Gly-(Arg)₅-Gln-(Arg)₄-NH₂; (SEQ ID NO: 154) Ac-Nle-c(Cys-D-Ala-His-D-Phe-Arg-Trp-Cys)-(β-Ala)₂-(Arg)₅-Gln-(Arg)₄-NH₂; (SEQ ID NO: 155) Ac-Nle-c(Cys-D-Ala-His-D-Phe-Arg-Trp-Cys)-(β-Ala)₂-Gly-(Arg)₅-Gln-(Arg)₄-NH₂; (SEQ ID NO: 155) Ac-Nle-c(Cys-D-Ala-His-D-Phe-Arg-Trp-Cys)-(β-Ala)₂-Tyr-Gly-(Arg)₅-Gln-(Arg)₄- NH₂; (SEQ ID NO: 157) Ac-Nle-c(Cys-D-Ala-His-D-Phe-Arg-Trp-Cys)-Doc-(Arg)₅-Gln-(Arg)₄-NH₂; (SEQ ID NO: 156) Ac-Nle-c(Cys-D-Ala-His-D-Phe-Arg-Trp-Cys)-Doc-Gly-(Arg)₅-Gln-(Arg)₄-NH₂; (SEQ ID NO: 156) Ac-Nle-c(Cys-D-Ala-His-D-Phe-Arg-Trp-Cys)-Doc-Tyr-Gly-(Arg)₅-Gln-(Arg)₄-NH₂; (SEQ ID NO: 157) Ac-Nle-c(Cys-D-Ala-His-D-Phe-Arg-Trp-Cys)-(Doc)₂-(Arg)₅-Gln-(Arg)₄-NH₂; (SEQ ID NO: 158) Ac-Nle-c(Cys-D-Ala-His-D-Phe-Arg-Trp-Cys)-(Doc)₂-Gly-(Arg)₅-Gln-(Arg)₄-NH₂; (SEQ ID NO: 158) Ac-Nle-c(Cys-D-Ala-His-D-Phe-Arg-Trp-Cys)-(Doc)₂-Tyr-Gly-(Arg)₅-Gln-(Arg)₄-NH₂; (SEQ ID NO: 159) Ac-Nle-c(Cys-His-D-Phe-Arg-Trp-Gaba-Cys)-β-Ala-Tyr-Gly-(Arg)₅-Gln-(Arg)₃-NH₂; (SEQ ID NO: 160) Ac-Nle-c(Cys-His-D-Phe-Arg-Trp-Gaba-Cys)-β-Ala-(Arg)₅-Gln-(Arg)₃-NH₂; (SEQ ID NO: 161) Ac-Nle-c(Asp-His-D-Phe-Arg-Trp-Ala-Lys)-β-Ala-Tyr-Gly-(Arg)₅-Gln-(Arg)₃-NH₂; (SEQ ID NO: 162) Ac-Nle-c(Asp-His-D-Phe-Arg-Trp-Ala-Lys)-β-Ala-(Arg)₅-Gln-(Arg)₃-NH₂; (SEQ ID NO: 164) Ac-Nle-c(Asp-His-D-Phe-Arg-Trp-Lys)-β-Ala-Tyr-Gly-(Arg)₅-Gln-(Arg)₃-NH₂; (SEQ ID NO: 163) Ac-Nle-c(Asp-His-D-Phe-Arg-Trp-Lys)-β-Ala-Gly-(Arg)₅-Gln-(Arg)₃-NH₂; (SEQ ID NO: 163) Ac-Nle-c(Asp-His-D-Phe-Arg-Trp-Lys)-β-Ala-(Arg)₅-Gln-(Arg)₃-NH₂; (SEQ ID NO: 164) Ac-Nle-c(Asp-His-D-Phe-Arg-Trp-Lys)-(β-Ala)₂-Tyr-Gly-(Arg)₅-Gln-(Arg)₃-NH₂; (SEQ ID NO: 165) Ac-Nle-c(Asp-His-D-Phe-Arg-Trp-Lys)-(β-Ala)₂-Gly-(Arg)₅-Gln-(Arg)₃-NH₂; (SEQ ID NO: 165) Ac-Nle-c(Asp-His-D-Phe-Arg-Trp-Lys)-(β-Ala)₂-(Arg)₅-Gln-(Arg)₃-NH₂; (SEQ ID NO: 166) Ac-Nle-c(Asp-His-D-Phe-Arg-Trp-Lys)-Doc-Tyr-Gly-(Arg)₅-Gln-(Arg)₃-NH₂; (SEQ ID NO: 166) Ac-Nle-c(Asp-His-D-Phe-Arg-Trp-Lys)-Doc-Gly-(Arg)₅-Gln-(Arg)₃-NH₂; (SEQ ID NO: 168) Ac-Nle-c(Asp-His-D-Phe-Arg-Trp-Lys)-Doc-(Arg)₅-Gln-(Arg)₃-NH₂; (SEQ ID NO: 167) Ac-Nle-c(Asp-His-D-Phe-Arg-Trp-Lys)-(Doc)₂-Tyr-Gly-(Arg)₅-Gln-(Arg)₃-NH₂; (SEQ ID NO: 167) Ac-Nle-c(Asp-His-D-Phe-Arg-Trp-Lys)-(Doc)₂-Gly-(Arg)₅-Gln-(Arg)₃-NH₂; (SEQ ID NO: 168) Ac-Nle-c(Asp-His-D-Phe-Arg-Trp-Lys)-(Doc)₂-(Arg)₅-Gln-(Arg)₃-NH₂; (SEQ ID NO: 170) Ac-Nle-c(Asp-His-D-Phe-Arg-Trp-Lys)-β-Ala-Tyr-Gly-(Arg)₅-Gln-(Arg)₄-NH₂; (SEQ ID NO: 169) Ac-Nle-c(Asp-His-D-Phe-Arg-Trp-Lys)-β-Ala-Gly-(Arg)₅-Gln-(Arg)₄-NH₂; (SEQ ID NO: 169) Ac-Nle-c(Asp-His-D-Phe-Arg-Trp-Lys)-β-Ala-(Arg)₅-Gln-(Arg)₄-NH₂; (SEQ ID NO: 170) Ac-Nle-c(Asp-His-D-Phe-Arg-Trp-Lys)-(β-Ala)₂-Tyr-Gly-(Arg)₅-Gln-(Arg)₄-NH₂; (SEQ ID NO: 171) Ac-Nle-c(Asp-His-D-Phe-Arg-Trp-Lys)-(β-Ala)₂-Gly-(Arg)₅-Gln-(Arg)₄-NH₂; (SEQ ID NO: 171) Ac-Nle-c(Asp-His-D-Phe-Arg-Trp-Lys)-(β-Ala)₂-(Arg)₅-Gln-(Arg)₄-NH₂; (SEQ ID NO: 173) Ac-Nle-c(Asp-His-D-Phe-Arg-Trp-Lys)-Doc-Tyr-Gly-(Arg)₅-Gln-(Arg)₄-NH₂; (SEQ ID NO: 172) Ac-Nle-c(Asp-His-D-Phe-Arg-Trp-Lys)-Doc-Gly-(Arg)₅-Gln-(Arg)₄-NH₂; (SEQ ID NO: 172) Ac-Nle-c(Asp-His-D-Phe-Arg-Trp-Lys)-Doc-(Arg)₅-Gln-(Arg)₄-NH₂; (SEQ ID NO: 173) Ac-Nle-c(Asp-His-D-Phe-Arg-Trp-Lys)-(Doc)₂-Tyr-Gly-(Arg)₅-Gln-(Arg)₄-NH₂; (SEQ ID NO: 174) Ac-Nle-c(Asp-His-D-Phe-Arg-Trp-Lys)-(Doc)₂-Gly-(Arg)₅-Gln-(Arg)₄-NH₂; (SEQ ID NO: 174) Ac-Nle-c(Asp-His-D-Phe-Arg-Trp-Lys)-(Doc)₂-(Arg)₅-Gln-(Arg)₄-NH₂; (SEQ ID NO: 175) Ac-Nle-c(Asp-His-D-Phe-Arg-Trp-β-Ala-Lys)-β-Ala-Tyr-Gly-(Arg)₅-Gln-(Arg)₃-NH₂; (SEQ ID NO: 176) Ac-Nle-c(Asp-His-D-Phe-Arg-Trp-β-Ala-Lys)-β-Ala-(Arg)₅-Gln-(Arg)₃-NH₂; (SEQ ID NO: 177) Ac-Nle-c(Cys-His-D-Phe-Arg-Trp-Ahx-Cys)-β-Ala-Tyr-Gly-(Arg)₅-Gln-(Arg)₃-NH₂; (SEQ ID NO: 178) Ac-Nle-c(Cys-His-D-Phe-Arg-Trp-Ahx-Cys)-β-Ala-(Arg)₅-Gln-(Arg)₃-NH₂; (SEQ ID NO: 179) D-Phe-c(Cys-His-D-Phe-Arg-Trp-β-Ala-D-Cys)-Thr-β-Ala-Tyr-Gly-(Arg)₅-Gln-(Arg)₃- NH₂; (SEQ ID NO: 180) D-Phe-c(Cys-His-D-Phe-Arg-Trp-β-Ala-D-Cys)-Thr-β-Ala-(Arg)₅-Gln-(Arg)₃-NH₂; (SEQ ID NO: 181) Ac-Nle-c(Cys-His-D-Phe-Arg-Trp-Apn-Cys)-β-Ala-Tyr-Gly-(Arg)₅-Gln-(Arg)₃-NH₂; (SEQ ID NO: 182) Ac-Nle-c(Cys-His-D-Phe-Arg-Trp-Apn-Cys)-β-Ala-(Arg)₅-Gln-(Arg)₃-NH₂; (SEQ ID NO: 183) Ac-Cha-c(Asp-His-D-Phe-Arg-Trp-Gaba-Lys)-β-Ala-Tyr-Gly-(Arg)₅-Gln-(Arg)₃-NH₂; (SEQ ID NO: 184) Ac-Cha-c(Asp-His-D-Phe-Arg-Trp-Gaba-Lys)-β-Ala-(Arg)₅-Gln-(Arg)₃-NH₂; (SEQ ID NO: 183) Ac-Nle-c(Asp-His-D-Phe-Arg-Trp-Gaba-Lys)-β-Ala-Tyr-Gly-(Arg)₅-Gln-(Arg)₃-NH₂; (SEQ ID NO: 185) Ac-Nle-c(Asp-His-D-Phe-Arg-Trp-Gaba-Lys)-β-Ala-(Arg)₅-Gln-(Arg)₃-NH₂; (SEQ ID NO: 186) Ac-Chg-c(Asp-His-D-Phe-Arg-Trp-Gaba-Lys)-β-Ala-Tyr-Gly-(Arg)₅-Gln-(Arg)₃-NH₂; (SEQ ID NO: 185) Ac-Chg-c(Asp-His-D-Phe-Arg-Trp-Gaba-Lys)-β-Ala-(Arg)₅-Gln-(Arg)₃-NH₂; (SEQ ID NO: 186) Ac-hCha-c(Asp-His-D-Phe-Arg-Trp-Gaba-Lys)-β-Ala-Tyr-Gly-(Arg)₅-Gln-(Arg)₃- NH₂; (SEQ ID NO: 188) Ac-hCha-c(Asp-His-D-Phe-Arg-Trp-Gaba-Lys)-β-Ala-(Arg)₅-Gln-(Arg)₃-NH₂; (SEQ ID NO: 187) Ac-hCha-c(Asp-His-D-Phe-Arg-Trp-Gaba-Lys)-(β-Ala)₂-Tyr-Gly-(Arg)₅-Gln-(Arg)₃- NH₂; (SEQ ID NO: 188) Ac-hCha-c(Asp-His-D-Phe-Arg-Trp-Gaba-Lys)-(β-Ala)₂-(Arg)₅-Gln-(Arg)₃-NH₂; (SEQ ID NO: 189) Ac-hCha-c(Asp-His-D-Phe-Arg-Trp-Gaba-Lys)-Doc-Tyr-Gly-(Arg)₅-Gln-(Arg)₃-NH₂; (SEQ ID NO: 190) Ac-hCha-c(Asp-His-D-Phe-Arg-Trp-Gaba-Lys)-Doc-(Arg)₅-Gln-(Arg)₃-NH₂; (SEQ ID NO: 189) Ac-hCha-c(Asp-His-D-Phe-Arg-Trp-Gaba-Lys)-(Doc)₂-Tyr-Gly-(Arg)₅-Gln-(Arg)₃- NH₂; (SEQ ID NO: 190) Ac-hCha-c(Asp-His-D-Phe-Arg-Trp-Gaba-Lys)-(Doc)₂-(Arg)₅-Gln-(Arg)₃-NH₂; (SEQ ID NO: 191) Ac-hCha-c(Asp-His-D-Phe-Arg-Trp-Gaba-Lys)-β-Ala-Tyr-Gly-(Arg)₅-Gln-(Arg)₄- NH₂; (SEQ ID NO: 192) Ac-hCha-c(Asp-His-D-Phe-Arg-Trp-Gaba-Lys)-β-Ala-(Arg)₅-Gln-(Arg)₄-NH₂; (SEQ ID NO: 191) Ac-hCha-c(Asp-His-D-Phe-Arg-Trp-Gaba-Lys)-(β-Ala)₂-Tyr-Gly-(Arg)₅-Gln-(Arg)₄- NH₂; (SEQ ID NO: 192) Ac-hCha-c(Asp-His-D-Phe-Arg-Trp-Gaba-Lys)-(β-Ala)₂-(Arg)₅-Gln-(Arg)₄-NH₂; (SEQ ID NO: 193) Ac-hCha-c(Asp-His-D-Phe-Arg-Trp-Gaba-Lys)-Doc-Tyr-Gly-(Arg)₅-Gln-(Arg)₄-NH₂; (SEQ ID NO: 194) Ac-hCha-c(Asp-His-D-Phe-Arg-Trp-Gaba-Lys)-Doc-(Arg)₅-Gln-(Arg)₄-NH₂; (SEQ ID NO: 193) Ac-hCha-c(Asp-His-D-Phe-Arg-Trp-Gaba-Lys)-(Doc)₂-Tyr-Gly-(Arg)₅-Gln-(Arg)₄- NH₂; (SEQ ID NO: 194) Ac-hCha-c(Asp-His-D-Phe-Arg-Trp-Gaba-Lys)-(Doc)₂-(Arg)₅-Gln-(Arg)₄-NH₂; (SEQ ID NO: 195) Ac-D-Chg-c(Asp-His-D-Phe-Arg-Trp-Gaba-Lys)-β-Ala-Tyr-Gly-(Arg)₅-Gln-(Arg)₃- NH₂; (SEQ ID NO: 196) Ac-D-Chg-c(Asp-His-D-Phe-Arg-Trp-Gaba-Lys)-β-Ala-(Arg)₅-Gln-(Arg)₃-NH₂; (SEQ ID NO: 197) Ac-hPhe-c(Asp-His-D-Phe-Arg-Trp-Gaba-Lys)-β-Ala-Tyr-Gly-(Arg)₅-Gln-(Arg)₃-NH₂; (SEQ ID NO: 198) Ac-hPhe-c(Asp-His-D-Phe-Arg-Trp-Gaba-Lys)-β-Ala-(Arg)₅-Gln-(Arg)₃-NH₂; (SEQ ID NO: 199) Ac-Nle-c(Cys-His-D-Phe-Arg-D-Trp-Apn-Cys)-β-Ala-Tyr-Gly-(Arg)₅-Gln-(Arg)₃- NH₂; (SEQ ID NO: 200) Ac-Nle-c(Cys-His-D-Phe-Arg-D-Trp-Apn-Cys)-β-Ala-(Arg)₅-Gln-(Arg)₃-NH₂; (SEQ ID NO: 199) Ac-Nle-c(Cys-His-D-Phe-Arg-D-Trp-Ahx-Cys)-β-Ala-Tyr-Gly-(Arg)₅-Gln-(Arg)₃-NH₂; (SEQ ID NO: 200) Ac-Nle-c(Cys-His-D-Phe-Arg-D-Trp-Ahx-Cys)-β-Ala-(Arg)₅-Gln-(Arg)₃-NH₂; (SEQ ID NO: 201) Ac-Nle-c(Cys-His-D-Phe-Arg-D-Trp-β-Ala-Cys)-β-Ala-Tyr-Gly-(Arg)₅-Gln-(Arg)₃- NH₂; (SEQ ID NO: 202) Ac-Nle-c(Cys-His-D-Phe-Arg-D-Trp-β-Ala-Cys)-β-Ala-(Arg)₅-Gln-(Arg)₃-NH₂; (SEQ ID NO: 203) Ac-Nle-c(Cys-D-Ala-His-D-Phe-Arg-Trp-Pen)-β-Ala-Tyr-Gly-(Arg)₅-Gln-(Arg)₃-NH₂; (SEQ ID NO: 203) Ac-Nle-c(Cys-D-Ala-His-D-Phe-Arg-Trp-Pen)-β-Ala-Gly-(Arg)₅-Gln-(Arg)₃-NH₂; (SEQ ID NO: 205) Ac-Nle-c(Cys-D-Ala-His-D-Phe-Arg-Trp-Pen)-β-Ala-(Arg)₅-Gln-(Arg)₃-NH₂; (SEQ ID NO: 204) Ac-Nle-c(Cys-D-Ala-His-D-Phe-Arg-Trp-Pen)-(β-Ala)₂-Tyr-Gly-(Arg)₅-Gln-(Arg)₃- NH₂; (SEQ ID NO: 204) Ac-Nle-c(Cys-D-Ala-His-D-Phe-Arg-Trp-Pen)-(β-Ala)₂-Gly-(Arg)₅-Gln-(Arg)₃-NH₂; (SEQ ID NO: 205) Ac-Nle-c(Cys-D-Ala-His-D-Phe-Arg-Trp-Pen)-(β-Ala)₂-(Arg)₅-Gln-(Arg)₃-NH₂; (SEQ ID NO: 207) Ac-Nle-c(Cys-D-Ala-His-D-Phe-Arg-Trp-Pen)-Doc-Tyr-Gly-(Arg)₅-Gln-(Arg)₃-NH₂; (SEQ ID NO: 206) Ac-Nle-c(Cys-D-Ala-His-D-Phe-Arg-Trp-Pen)-Doc-Gly-(Arg)₅-Gln-(Arg)₃-NH₂; (SEQ ID NO: 206) Ac-Nle-c(Cys-D-Ala-His-D-Phe-Arg-Trp-Pen)-Doc-(Arg)₅-Gln-(Arg)₃-NH₂; (SEQ ID NO: 207) Ac-Nle-c(Cys-D-Ala-His-D-Phe-Arg-Trp-Pen)-(Doc)₂-Tyr-Gly-(Arg)₅-Gln-(Arg)₃-NH₂; (SEQ ID NO: 208) Ac-Nle-c(Cys-D-Ala-His-D-Phe-Arg-Trp-Pen)-(Doc)₂-Gly-(Arg)₅-Gln-(Arg)₃-NH₂; (SEQ ID NO: 208) Ac-Nle-c(Cys-D-Ala-His-D-Phe-Arg-Trp-Pen)-(Doc)₂-(Arg)₅-Gln-(Arg)₃-NH₂; (SEQ ID NO: 209) D-Phe-c(Cys-His-D-(Et)Tyr-Arg-Trp-β-Ala-D-Cys)-β-Ala-Tyr-Gly-(Arg)₅-Gln-(Arg)₃- NH₂; (SEQ ID NO: 210) D-Phe-c(Cys-His-D-(Et)Tyr-Arg-Trp-β-Ala-D-Cys)-β-Ala-(Arg)₅-Gln-(Arg)₃-NH₂; (SEQ ID NO: 209) D-Phe-c(Cys-His-D-(Et)Tyr-Arg-Trp-β-Ala-D-Cys)-β-Ala-Gly-(Arg)₅-Gln-(Arg)₃-NH₂; (SEQ ID NO: 211) D-Phe-c(Cys-His-D-(Et)Tyr-Arg-Trp-β-Ala-D-Cys)-β-Ala-(Arg)₅-Gln-(Arg)₄-NH₂; (SEQ ID NO: 212) D-Phe-c(Cys-His-D-(Et)Tyr-Arg-Trp-β-Ala-D-Cys)-(β-Ala)₂-Tyr-Gly-(Arg)₅-Gln- (Arg)₃-NH₂; (SEQ ID NO: 213) D-Phe-c(Cys-His-D-(Et)Tyr-Arg-Trp-β-Ala-D-Cys)-(β-Ala)₂-(Arg)₅-Gln-(Arg)₃-NH₂; (SEQ ID NO: 213) D-Phe-c(Cys-His-D-(Et)Tyr-Arg-Trp-β-Ala-D-Cys)-(β-Ala)₂-Gly-(Arg)₅-Gln-(Arg)₃- NH₂; (SEQ ID NO: 267) D-Phe-c(Cys-His-D-(Et)Tyr-Arg-Trp-β-Ala-D-Cys)-(β-Ala)₂-(Arg)₅-Gln-(Arg)₄-NH₂; (SEQ ID NO: 214) D-Phe-c(Cys-His-D-(Et)Tyr-Arg-Trp-β-Ala-D-Cys)-Doc-Tyr-Gly-(Arg)₅-Gln-(Arg)₃- NH₂; (SEQ ID NO: 216) D-Phe-c(Cys-His-D-(Et)Tyr-Arg-Trp-β-Ala-D-Cys)-Doc-(Arg)₅-Gln-(Arg)₃-NH₂; (SEQ ID NO: 214) D-Phe-c(Cys-His-D-(Et)Tyr-Arg-Trp-β-Ala-D-Cys)-Doc-Gly-(Arg)₅-Gln-(Arg)₃-NH₂; (SEQ ID NO: 217) D-Phe-c(Cys-His-D-(Et)Tyr-Arg-Trp-β-Ala-D-Cys)-Doc-(Arg)₅-Gln-(Arg)₄-NH₂; (SEQ ID NO: 215) D-Phe-c(Cys-His-D-(Et)Tyr-Arg-Trp-β-Ala-D-Cys)-(Doc)₂-Tyr-Gly-(Arg)₅-Gln-(Arg)₃- NH₂; (SEQ ID NO: 216) D-Phe-c(Cys-His-D-(Et)Tyr-Arg-Trp-β-Ala-D-Cys)-(Doc)₂-(Arg)₅-Gln-(Arg)₃-NH₂; (SEQ ID NO: 215) D-Phe-c(Cys-His-D-(Et)Tyr-Arg-Trp-β-Ala-D-Cys)-(Doc)₂-Gly-(Arg)₅-Gln-(Arg)₃- NH₂; (SEQ ID NO: 217) D-Phe-c(Cys-His-D-(Et)Tyr-Arg-Trp-β-Ala-D-Cys)-(Doc)₂-(Arg)₅-Gln-(Arg)₄-NH₂; (SEQ ID NO: 218) D-Phe-c(Cys-His-D-(Et)Tyr-hArg-Trp-β-Ala-D-Cys)-Thr-β-Ala-Tyr-Gly-(Arg)₅-Gln- (Arg)₃-NH₂; (SEQ ID NO: 219) D-Phe-c(Cys-His-D-(Et)Tyr-hArg-Trp-β-Ala-D-Cys)-Thr-β-Ala-(Arg)₅-Gln-(Arg)₃- NH₂; (SEQ ID NO: 218) D-Phe-c(Cys-His-D-(Et)Tyr-hArg-Trp-β-Ala-D-Cys)-Thr-(β-Ala)₂-Tyr-Gly-(Arg)₅-Gln- (Arg)₃-NH₂; (SEQ ID NO: 219) D-Phe-c(Cys-His-D-(Et)Tyr-hArg-Trp-β-Ala-D-Cys)-Thr-(β-Ala)₂-(Arg)₅-Gln-(Arg)₃- NH₂; (SEQ ID NO: 221) D-Phe-c(Cys-His-D-(Et)Tyr-hArg-Trp-β-Ala-D-Cys)-Thr-Doc-Tyr-Gly-(Arg)₅-Gln- (Arg)₃-NH₂; (SEQ ID NO: 220) D-Phe-c(Cys-His-D-(Et)Tyr-hArg-Trp-β-Ala-D-Cys)-Thr-Doc-(Arg)₅-Gln-(Arg)₃-NH₂; (SEQ ID NO: 221) D-Phe-c(Cys-His-D-(Et)Tyr-hArg-Trp-β-Ala-D-Cys)-Thr-(Doc)₂-Tyr-Gly-(Arg)₅-Gln- (Arg)₃-NH₂; (SEQ ID NO: 222) D-Phe-c(Cys-His-D-(Et)Tyr-hArg-Trp-β-Ala-D-Cys)-Thr-β-Ala-Tyr-Gly-(Arg)₅-Gln- (Arg)₄-NH₂; (SEQ ID NO: 223) D-Phe-c(Cys-His-D-(Et)Tyr-hArg-Trp-β-Ala-D-Cys)-Thr-β-Ala-(Arg)₅-Gln-(Arg)₄- NH₂; (SEQ ID NO: 222) D-Phe-c(Cys-His-D-(Et)Tyr-hArg-Trp-β-Ala-D-Cys)-Thr-(β-Ala)₂-Tyr-Gly-(Arg)₅-Gln- (Arg)₄-NH₂; (SEQ ID NO: 223) D-Phe-c(Cys-His-D-(Et)Tyr-hArg-Trp-β-Ala-D-Cys)-Thr-(β-Ala)₂-(Arg)₅-Gln-(Arg)₄- NH₂; (SEQ ID NO: 224) D-Phe-c(Cys-His-D-(Et)Tyr-hArg-Trp-β-Ala-D-Cys)-Thr-Doc-Tyr-Gly-(Arg)₅-Gln- (Arg)₄-NH₂; (SEQ ID NO: 225) D-Phe-c(Cys-His-D-(Et)Tyr-hArg-Trp-β-Ala-D-Cys)-Thr-Doc-(Arg)₅-Gln-(Arg)₄-NH₂; (SEQ ID NO: 224) D-Phe-c(Cys-His-D-(Et)Tyr-hArg-Trp-β-Ala-D-Cys)-Thr-(Doc)₂-Tyr-Gly-(Arg)₅-Gln- (Arg)₄-NH₂; (SEQ ID NO: 225) D-Phe-c(Cys-His-D-(Et)Tyr-hArg-Trp-β-Ala-D-Cys)-Thr-(Doc)₂-(Arg)₅-Gln-(Arg)₄- NH₂; (SEQ ID NO: 227) D-Phe-c(Cys-His-D-(Et)Tyr-hArg-Bip-β-Ala-D-Cys)-Thr-β-Ala-Tyr-Gly-(Arg)₅-Gln- (Arg)₃-NH₂; (SEQ ID NO: 226) D-Phe-c(Cys-His-D-(Et)Tyr-hArg-Bip-β-Ala-D-Cys)-Thr-β-Ala-Tyr-Gly-(Arg)₅-Gln- (Arg)₄-NH₂; (SEQ ID NO: 228) D-Phe-c(Cys-His-D-(Et)Tyr-hArg-Bip-β-Ala-D-Cys)-Thr-β-Ala-(Arg)₅-Gln-(Arg)₃- NH₂; (SEQ ID NO: 227) D-Phe-c(Cys-His-D-(Et)Tyr-hArg-Bip-β-Ala-D-Cys)-Thr-(β-Ala)₂-Tyr-Gly-(Arg)₅-Gln- (Arg)₃-NH₂; (SEQ ID NO: 228) D-Phe-c(Cys-His-D-(Et)Tyr-hArg-Bip-β-Ala-D-Cys)-Thr-(β-Ala)₂-(Arg)₅-Gln-(Arg)₃- NH₂; (SEQ ID NO: 229) D-Phe-c(Cys-His-D-(Et)Tyr-hArg-Bip-β-Ala-D-Cys)-Thr-Doc-Tyr-Gly-(Arg)₅-Gln- (Arg)₃-NH₂; (SEQ ID NO: 230) D-Phe-c(Cys-His-D-(Et)Tyr-hArg-Bip-β-Ala-D-Cys)-Thr-Doc-Tyr-Gly-(Arg)₅-Gln- (Arg)₄-NH₂; (SEQ ID NO: 232) D-Phe-c(Cys-His-D-(Et)Tyr-hArg-Bip-β-Ala-D-Cys)-Thr-Doc-(Arg)₅-Gln-(Arg)₃-NH₂; (SEQ ID NO: 231) D-Phe-c(Cys-His-D-(Et)Tyr-hArg-Bip-β-Ala-D-Cys)-Thr-(Doc)₂-Tyr-Gly-(Arg)₅-Gln- (Arg)₃-NH₂; (SEQ ID NO: 232) D-Phe-c(Cys-His-D-(Et)Tyr-hArg-Bip-β-Ala-D-Cys)-Thr-(Doc)₂-(Arg)₅-Gln-(Arg)₃- NH₂; (SEQ ID NO: 233) Ac-Nle-c(Cys-D-Ala-His-D-Phe-Arg-Trp-Gly-Cys)-β-Ala-Tyr-Gly-(Arg)₅-Gln-(Arg)₃- NH₂; (SEQ ID NO: 234) Ac-Nle-c(Cys-D-Ala-His-D-Phe-Arg-Trp-Gly-Cys)-β-Ala-(Arg)₅-Gln-(Arg)₃-NH₂; (SEQ ID NO: 235) Nle-c(Cys-His-D-Phe-Arg-Trp-Apn-Cys)-β-Ala-Tyr-Gly-(Arg)₅-Gln-(Arg)₃-NH₂; (SEQ ID NO: 236) Nle-c(Cys-His-D-Phe-Arg-Trp-Apn-Cys)-β-Ala-(Arg)₅-Gln-(Arg)₃-NH₂; (SEQ ID NO: 235) Nle-c(Cys-His-D-Phe-Arg-Trp-Apn-Cys)-(β-Ala)₂-Tyr-Gly-(Arg)₅-Gln-(Arg)₃-NH₂; (SEQ ID NO: 236) Nle-c(Cys-His-D-Phe-Arg-Trp-Apn-Cys)-(β-Ala)₂-(Arg)₅-Gln-(Arg)₃-NH₂; (SEQ ID NO: 237) Nle-c(Cys-His-D-Phe-Arg-Trp-Apn-Cys)-β-Ala-Tyr-Gly-(Arg)₅-Gln-(Arg)₄-NH₂; (SEQ ID NO: 238) Nle-c(Cys-His-D-Phe-Arg-Trp-Apn-Cys)-β-Ala-(Arg)₅-Gln-(Arg)₄-NH₂; (SEQ ID NO: 237) Nle-c(Cys-His-D-Phe-Arg-Trp-Apn-Cys)-(β-Ala)₂-Tyr-Gly-(Arg)₅-Gln-(Arg)₄-NH₂; (SEQ ID NO: 238) Nle-c(Cys-His-D-Phe-Arg-Trp-Apn-Cys)-(β-Ala)₂-(Arg)₅-Gln-(Arg)₄-NH₂; (SEQ ID NO: 239) Nle-c(Cys-His-D-Phe-Arg-Trp-Apn-Cys)-Doc-Tyr-Gly-(Arg)₅-Gln-(Arg)₃-NH₂; (SEQ ID NO: 240) Nle-c(Cys-His-D-Phe-Arg-Trp-Apn-Cys)-Doc-(Arg)₅-Gln-(Arg)₃-NH₂; (SEQ ID NO: 239) Nle-c(Cys-His-D-Phe-Arg-Trp-Apn-Cys)-(Doc)₂-Tyr-Gly-(Arg)₅-Gln-(Arg)₃-NH₂; (SEQ ID NO: 240) Nle-c(Cys-His-D-Phe-Arg-Trp-Apn-Cys)-(Doc)₂-(Arg)₅-Gln-(Arg)₃-NH₂; (SEQ ID NO: 241) Nle-c(Cys-His-D-Phe-Arg-Trp-Apn-Cys)-Doc-Tyr-Gly-(Arg)₅-Gln-(Arg)₄-NH₂; (SEQ ID NO: 242) Nle-c(Cys-His-D-Phe-Arg-Trp-Apn-Cys)-Doc-(Arg)₅-Gln-(Arg)₄-NH₂; (SEQ ID NO: 241) Nle-c(Cys-His-D-Phe-Arg-Trp-Apn-Cys)-(Doc)₂-Tyr-Gly-(Arg)₅-Gln-(Arg)₄-NH₂; (SEQ ID NO: 242) Nle-c(Cys-His-D-Phe-Arg-Trp-Apn-Cys)-(Doc)₂-(Arg)₅-Gln-(Arg)₄-NH₂; (SEQ ID NO: 243) Ac-Nle-c(Cys-D-Leu-His-D-Phe-Arg-Trp-Cys)-β-Ala-Tyr-Gly-(Arg)₅-Gln-(Arg)₃-NH₂; (SEQ ID NO: 244) Ac-Nle-c(Cys-D-Leu-His-D-Phe-Arg-Trp-Cys)-β-Ala-(Arg)₅-Gln-(Arg)₃-NH₂; (SEQ ID NO: 243) Ac-Nle-c(Cys-D-Leu-His-D-Phe-Arg-Trp-Cys)-(β-Ala)₂-Tyr-Gly-(Arg)₅-Gln-(Arg)₃- NH₂; (SEQ ID NO: 244) Ac-Nle-c(Cys-D-Leu-His-D-Phe-Arg-Trp-Cys)-(β-Ala)₂-(Arg)₅-Gln-(Arg)₃-NH₂; (SEQ ID NO: 245) Ac-Nle-c(Cys-D-Leu-His-D-Phe-Arg-Trp-Cys)-Doc-Tyr-Gly-(Arg)₅-Gln-(Arg)₃-NH₂; (SEQ ID NO: 246) Ac-Nle-c(Cys-D-Leu-His-D-Phe-Arg-Trp-Cys)-Doc-(Arg)₅-Gln-(Arg)₃-NH₂; (SEQ ID NO: 245) Ac-Nle-c(Cys-D-Leu-His-D-Phe-Arg-Trp-Cys)-(Doc)₂-Tyr-Gly-(Arg)₅-Gln-(Arg)₃- NH₂; (SEQ ID NO: 246) Ac-Nle-c(Cys-D-Leu-His-D-Phe-Arg-Trp-Cys)-(Doc)₂-(Arg)₅-Gln-(Arg)₃-NH₂; (SEQ ID NO: 247) Ac-Nle-c(Cys-D-Leu-His-D-Phe-Arg-Trp-Cys)-β-Ala-Tyr-Gly-(Arg)₅-Gln-(Arg)₄-NH₂; (SEQ ID NO: 248) Ac-Nle-c(Cys-D-Leu-His-D-Phe-Arg-Trp-Cys)-β-Ala-(Arg)₅-Gln-(Arg)₄-NH₂; (SEQ ID NO: 247) Ac-Nle-c(Cys-D-Leu-His-D-Phe-Arg-Trp-Cys)-(β-Ala)₂-Tyr-Gly-(Arg)₅-Gln-(Arg)₄- NH₂; (SEQ ID NO: 248) Ac-Nle-c(Cys-D-Leu-His-D-Phe-Arg-Trp-Cys)-(β-Ala)₂-(Arg)₅-Gln-(Arg)₄-NH₂; (SEQ ID NO: 249) Ac-Nle-c(Cys-D-Leu-His-D-Phe-Arg-Trp-Cys)-Doc-Tyr-Gly-(Arg)₅-Gln-(Arg)₄-NH₂; (SEQ ID NO: 250) Ac-Nle-c(Cys-D-Leu-His-D-Phe-Arg-Trp-Cys)-Doc-(Arg)₅-Gln-(Arg)₄-NH₂; (SEQ ID NO: 249) Ac-Nle-c(Cys-D-Leu-His-D-Phe-Arg-Trp-Cys)-(Doc)₂-Tyr-Gly-(Arg)₅-Gln-(Arg)₄- NH₂; (SEQ ID NO: 250) Ac-Nle-c(Cys-D-Leu-His-D-Phe-Arg-Trp-Cys)-(Doc)₂-(Arg)₅-Gln-(Arg)₄-NH₂; (SEQ ID NO: 251) Ac-Nle-c(Cys-D-Cha-His-D-Phe-Arg-Trp-Cys)-β-Ala-Tyr-Gly-(Arg)₅-Gln-(Arg)₃-NH₂; (SEQ ID NO: 252) Ac-Nle-c(Cys-D-Cha-His-D-Phe-Arg-Trp-Cys)-β-Ala-(Arg)₅-Gln-(Arg)₃-NH₂; (SEQ ID NO: 251) Ac-Nle-c(Cys-D-Cha-His-D-Phe-Arg-Trp-Cys)-(β-Ala)₂-Tyr-Gly-(Arg)₅-Gln-(Arg)₃- NH₂; (SEQ ID NO: 252) Ac-Nle-c(Cys-D-Cha-His-D-Phe-Arg-Trp-Cys)-(β-Ala)₂-(Arg)₅-Gln-(Arg)₃-NH₂; (SEQ ID NO: 253) Ac-Nle-c(Cys-D-Cha-His-D-Phe-Arg-Trp-Cys)-Doc-Tyr-Gly-(Arg)₅-Gln-(Arg)₃-NH₂; (SEQ ID NO: 254) Ac-Nle-c(Cys-D-Cha-His-D-Phe-Arg-Trp-Cys)-Doc-(Arg)₅-Gln-(Arg)₃-NH₂; (SEQ ID NO: 253) Ac-Nle-c(Cys-D-Cha-His-D-Phe-Arg-Trp-Cys)-(Doc)₂-Tyr-Gly-(Arg)₅-Gln-(Arg)₃- NH₂; (SEQ ID NO: 254) Ac-Nle-c(Cys-D-Cha-His-D-Phe-Arg-Trp-Cys)-(Doc)₂-(Arg)₅-Gln-(Arg)₃-NH₂; (SEQ ID NO: 255) Ac-Nle-c(Cys-D-Cha-His-D-Phe-Arg-Trp-Cys)-β-Ala-Tyr-Gly-(Arg)₅-Gln-(Arg)₄-NH₂; (SEQ ID NO: 256) Ac-Nle-c(Cys-D-Cha-His-D-Phe-Arg-Trp-Cys)-β-Ala-(Arg)₅-Gln-(Arg)₄-NH₂; (SEQ ID NO: 255) Ac-Nle-c(Cys-D-Cha-His-D-Phe-Arg-Trp-Cys)-(β-Ala)₂-Tyr-Gly-(Arg)₅-Gln-(Arg)₄- NH₂; (SEQ ID NO: 256) Ac-Nle-c(Cys-D-Cha-His-D-Phe-Arg-Trp-Cys)-(β-Ala)₂-(Arg)₅-Gln-(Arg)₄-NH₂; (SEQ ID NO: 257) Ac-Nle-c(Cys-D-Cha-His-D-Phe-Arg-Trp-Cys)-Doc-Tyr-Gly-(Arg)₅-Gln-(Arg)₄-NH₂; (SEQ ID NO: 258) Ac-Nle-c(Cys-D-Cha-His-D-Phe-Arg-Trp-Cys)-Doc-(Arg)₅-Gln-(Arg)₄-NH₂; (SEQ ID NO: 257) Ac-Nle-c(Cys-D-Cha-His-D-Phe-Arg-Trp-Cys)-(Doc)₂-Tyr-Gly-(Arg)₅-Gln-(Arg)₄- NH₂; (SEQ ID NO: 258) Ac-Nle-c(Cys-D-Cha-His-D-Phe-Arg-Trp-Cys)-(Doc)₂-(Arg)₅-Gln-(Arg)₄-NH₂; (SEQ ID NO: 259) Nle-c(Cys-His-D-Phe-Arg-Trp-Gaba-Cys)-β-Ala-Tyr-Gly-(Arg)₅-Gln-(Arg)₃-NH₂; (SEQ ID NO: 260) Nle-c(Cys-His-D-Phe-Arg-Trp-Gaba-Cys)-β-Ala-(Arg)₅-Gln-(Arg)₃-NH₂; (SEQ ID NO: 259) Nle-c(Cys-His-D-Phe-Arg-Trp-Gaba-Cys)-(β-Ala)₂-Tyr-Gly-(Arg)₅-Gln-(Arg)₃-NH₂; (SEQ ID NO: 260) Nle-c(Cys-His-D-Phe-Arg-Trp-Gaba-Cys)-(β-Ala)₂-(Arg)₅-Gln-(Arg)₃-NH₂; (SEQ ID NO: 261) Nle-c(Cys-His-D-Phe-Arg-Trp-Gaba-Cys)-β-Ala-Tyr-Gly-(Arg)₅-Gln-(Arg)₄-NH₂; (SEQ ID NO: 262) Nle-c(Cys-His-D-Phe-Arg-Trp-Gaba-Cys)-β-Ala-(Arg)₅-Gln-(Arg)₄-NH₂; (SEQ ID NO: 261) Nle-c(Cys-His-D-Phe-Arg-Trp-Gaba-Cys)-(β-Ala)₂-Tyr-Gly-(Arg)₅-Gln-(Arg)₄-NH₂; (SEQ ID NO: 262) Nle-c(Cys-His-D-Phe-Arg-Trp-Gaba-Cys)-(β-Ala)₂-(Arg)₅-Gln-(Arg)₄-NH₂; (SEQ ID NO: 263) Nle-c(Cys-His-D-Phe-Arg-Trp-Gaba-Cys)-Doc-Tyr-Gly-(Arg)₅-Gln-(Arg)₃-NH₂; (SEQ ID NO: 264) Nle-c(Cys-His-D-Phe-Arg-Trp-Gaba-Cys)-Doc-(Arg)₅-Gln-(Arg)₃-NH₂; (SEQ ID NO: 263) Nle-c(Cys-His-D-Phe-Arg-Trp-Gaba-Cys)-(Doc)₂-Tyr-Gly-(Arg)₅-Gln-(Arg)₃-NH₂; (SEQ ID NO: 264) Nle-c(Cys-His-D-Phe-Arg-Trp-Gaba-Cys)-(Doc)₂-(Arg)₅-Gln-(Arg)₃-NH₂; (SEQ ID NO: 265) Nle-c(Cys-His-D-Phe-Arg-Trp-Gaba-Cys)-Doc-Tyr-Gly-(Arg)₅-Gln-(Arg)₄-NH₂; (SEQ ID NO: 266) Nle-c(Cys-His-D-Phe-Arg-Trp-Gaba-Cys)-Doc-(Arg)₅-Gln-(Arg)₄-NH₂; (SEQ ID NO: 265) Nle-c(Cys-His-D-Phe-Arg-Trp-Gaba-Cys)-(Doc)₂-Tyr-Gly-(Arg)₅-Gln-(Arg)₄-NH₂; or (SEQ ID NO: 266) Nle-c(Cys-His-D-Phe-Arg-Trp-Gaba-Cys)-(Doc)₂-(Arg)₅-Gln-(Arg)₄-NH₂;; or pharmaceutically acceptable salts thereof.

In a fourth embodiment, the invention provides a method to treat insulin resistance in a mammalian subject, with or without weight loss, by the administration of a therapeutically effective amount of a melanocortin receptor compound according to Formula (IV), and pharmaceutically acceptable salts, hydrates, solvates and prodrugs thereof, with a compound having the following formula (formula (IV)):

Ac-c(Cys-Glu-His-A¹-Arg-A²-A³-Cys)-(Pro)₂-Lys-Asp-NH₂   (IV)

wherein: A¹ is the D-isomer of X-Phe or 2-Nal where X is halogen;

A² is Bal, 1-Nal, 2-Nal, or Trp; and A³ is Aib, Ala, β-Ala or Gly,

or pharmaceutically acceptable salts thereof.

Preferred compounds of the immediately foregoing formula discovered to treat insulin resistance in a mammalian subject, with or without weight loss, include the following:

(SEQ ID NO: 268) Ac-c(Cys-Glu-His-D-4-Br-Phe-Arg-Trp-Gly-Cys)- (Pro)₂-Lys-Asp-NH_(2;) (SEQ ID NO: 269) Ac-c(Cys-Glu-His-D-2-Nal-Arg-Trp-Ala-Cys)-(Pro)₂- Lys-Asp-NH₂; (SEQ ID NO: 269) Ac-c(Cys-Glu-His-D-2-Nal-Arg-2-Nal-Ala-Cys)- (Pro)₂-Lys-Asp-NH₂; (SEQ ID NO: 269) Ac-c(Cys-Glu-His-D-2-Nal-Arg-1-Nal-Ala-Cys)- (Pro)₂-Lys-Asp-NH₂; (SEQ ID NO: 2690) Ac-c(Cys-Glu-His-D-2-Nal-Arg-Bal-Ala-Cys)-(Pro)₂- Lys-Asp-NH₂; (SEQ ID NO: 270) Ac-c(Cys-Glu-His-D-2-Nal-Arg-2-Nal-β-Ala-Cys)- (Pro)₂-Lys-Asp-NH₂; or (SEQ ID NO: 270) Ac-c(Cys-Glu-His-D-2-Nal-Arg-2-Nal-Aib-Cys)- (Pro)₂-Lys-Asp-NH₂; or pharmaceutically acceptable salts thereof.

The invention additionally provides a method to treat insulin resistance in a mammalian subject, with or without weight loss, by the administration of a therapeutically effective amount of a melanocortin receptor compound modified with a hydantoin moiety according to Formula (V), (VI) or (VII), and pharmaceutically acceptable salts, hydrates, solvates or prodrugs thereof.

According to a fifth embodiment, the invention provides a method to treat insulin resistance in a mammalian subject, with or without weight loss, by the administration of a therapeutically effective amount of a melanocortin receptor ligand according to the following formula (Formula (V)), pharmaceutically-acceptable salts, hydrates, solvates and/or prodrugs thereof (see International Patent Application Number PCT/US08/06675 incorporated herein by reference in its entirety):

wherein

X is selected from the group consisting of —CH₂—S—S—CH₂—, —C(CH₃)₂—S—S—CH₂—, —CH₂—S—S—C(CH₃)₂—, —C(CH₃)₂—S—S—C(CH₃)₂—, —(CH₂)₂—S—S—CH₂—, —CH₂—S—S—(CH₂)₂—, —(CH₂)₂—S—S—(CH₂)₂—, —C(CH₃)₂—S—S—(CH₂)₂—, —(CH₂)₂—S—S—C(CH₃)₂—, —(CH₂) t-C(O)—NR⁸—(CH₂)_(r) and —(CH₂)_(r)—NR⁸—C(O)—(CH₂)_(t)—;

R¹ and R² each is, independently, H, (C₁-C₁₀)alkyl or substituted (C₁-C₁₀)alkyl;

R³ is —OH or —NH₂;

R⁴ and R⁵ each is, independently, H, (C₁-C₁₀)alkyl or substituted (C₁-C₁₀)alkyl;

X¹ is

A¹ is His, 2-Pal, 3-Pal, 4-Pal, (X¹,X²,X³,X⁴,X⁵)Phe, Taz, 2-Thi, 3-Thi or is deleted;

A² is D-Bal, D-1-Nal, D-2-Nal, D-Phe or D-(X¹,X²,X³,X⁴,X⁵)Phe;

A³ is Arg, hArg, Dab, Dap, Lys or Orn;

A⁴ is Bal, 1-Nal, 2-Nal, (X¹,X²,X³,X⁴,X⁵)Phe or Trp;

R⁶ and R⁷ each is, independently for each occurrence thereof, H, (C₁-C₁₀)alkyl, (C₁-C₁₀)heteroalkyl, aryl(C₁-C₅)alkyl, substituted (C₁-C₁₀)alkyl, substituted (C₁-C₁₀)heteroalkyl or substituted aryl(C₁-C₅)alkyl provided that R⁶ and R⁷ may be joined together to form a ring;

R⁸ is H, (C₁-C₁₀)alkyl or substituted (C₁-C₁₀)alkyl;

r is, independently for each occurrence thereof, 1, 2, 3, 4 or 5; and

t is, independently for each occurrence thereof, 1 or 2.

Preferrably, a compound according the foregoing formula found useful to treat insulin resistance in a mammalian subject, with or without weight loss, include compounds wherein X¹ is selected from the group consisting of:

Representative embodiments of the foregoing class of compounds useful to treat insulin resistance in a mammalian subject, with or without weight loss, are as follows:

(SEQ ID NO: 271) c[Hydantoin(C(O)-(Cys-D-Ala))-His-D-Phe-Arg-Trp- Cys]-NH₂; (SEQ ID NO: 271) c[Hydantoin(C(O)-(hCys-D-Ala))-His-D-Phe-Arg-Trp- Cys]-NH₂; (SEQ ID NO: 272) c[Hydantoin(C(O)-(Cys-D-Ala))-His-D-2-Nal-Arg-Trp- Cys]-NH₂; or (SEQ ID NO: 272) c[Hydantoin(C(O)-(hCys-D-Ala))-His-D-2-Nal-Arg- Trp-Cys]-NH₂; (SEQ ID NO: 273) c[Hydantoin(C(O)-(Asp-D-Ala))-His-D-Phe-Arg-Trp- Lys]-NH₂; (SEQ ID NO: 273) c[Hydantoin(C(O)-(Asp-D-Ala))-His-D-Phe-Arg-Trp- Orn]-NH₂; (SEQ ID NO: 273) c[Hydantoin(C(O)-(Asp-D-Ala))-His-D-Phe-Arg-Trp- Dab]-NH₂; or (SEQ ID NO: 273) c[Hydantoin(C(O)-(Asp-D-Ala))-His-D-Phe-Arg-Trp- Dap]-NH₂; (SEQ ID NO: 275) c[Hydantoin(C(O)-(Asp-His))-D-2-Nal-Arg-Trp- Lys]-NH₂; (SEQ ID NO: 274) c[Hydantoin(C(O)-(Asp-His))-D-Phe-Arg-Trp- Lys]-NH₂ (SEQ ID NO: 274) c[Hydantoin(C(O)-(Asp-A3c))-D-Phe-Arg-Trp- Lys]-NH₂; (SEQ ID NO: 274) c[Hydantoin(C(O)-(Asp-A5c))-D-Phe-Arg-Trp- Lys]-NH₂; (SEQ ID NO: 274) c[Hydantoin(C(O)-(Asp-A6c))-D-Phe-Arg-Trp- Lys]-NH₂; (SEQ ID NO: 275) c[Hydantoin(C(O)-(Asp-A3c))-D-2-Nal-Arg-Trp- Lys]-NH₂; (SEQ ID NO: 275) c[Hydantoin(C(O)-(Asp-A5c))-D-2-Nal-Arg-Trp- Lys]-NH₂; (SEQ ID NO: 275) c[Hydantoin(C(O)-(Asp-A6c))-D-2-Nal-Arg-Trp- Lys]-NH₂; (SEQ ID NO: 274) c[Hydantoin(C(O)-(Asp-Aic))-D-Phe-Arg-Trp- Lys]-NH₂; (SEQ ID NO: 274) c[Hydantoin(C(O)-(Asp-Apc))-D-Phe-Arg-Trp- Lys]-NH₂; (SEQ ID NO: 275) c[Hydantoin(C(O)-(Asp-Aic))-D-2-Nal-Arg-Trp- Lys]-NH₂; (SEQ ID NO: 275) c[Hydantoin(C(O)-(Asp-Apc))-D-2-Nal-Arg-Trp- Lys]-NH₂; (SEQ ID NO: 275) c[Hydantoin-(C(O)-(Asp-Aic))-D-2-Nal-Arg-Trp- Lys]-NH₂ (SEQ ID NO: 275) c[Hydantoin-(C(O)-(Asp-Apc))-D-2-Nal-Arg-Trp- Lys]-NH₂ (SEQ ID NO: 276) c[Hydantoin(C(O)-(Glu-D-Ala))-His-D-Phe-Arg-Trp- Orn]-NH₂; (SEQ ID NO: 276) c[Hydantoin(C(O)-(Glu-D-Ala))-His-D-Phe-Arg-Trp- Dab]-NH₂; or (SEQ ID NO: 276) c[Hydantoin(C(O)-(Glu-D-Ala))-His-D-Phe-Arg-Trp- Dap]-NH₂, (SEQ ID NO: 277) c[Hydantoin(C(O)-(Glu-His))-D-Phe-Arg-Trp-Dap]-NH₂

According to a sixth embodiment, the invention provides a method to treat insulin resistance in a mammalian subject, with or without weight loss, by the administration of a therapeutically effective amount of a melanocortin receptor compound according to Formula (VI), pharmaceutically-acceptable salts, hydrates, solvates and/or prodrugs thereof (see International Patent Application Number PCT/US08/06675 which is incorporated herein by reference in its entirety):

wherein

X¹ is

X² is

A¹ is Asp, Cys, D-Cys, Dab, Dap, Glu, Lys, Orn, Pen or D-Pen;

A² is an L- or D-amino acid;

A³ is His, 2-Pal, 3-Pal, 4-Pal, (X¹,X²,X³,X⁴,X⁵)Phe, Taz, 2-Thi or 3-Thi;

A⁴ is D-Bal, D-1-Nal, D-2-Nal, D-Phe or D-(X¹,X²,X³,X⁴,X⁵)Phe;

A⁵ is Arg, hArg, Dab, Dap, Lys or Orn;

A⁶ is Bal, 1-Nal, 2-Nal, (X¹,X²,X³,X⁴,X⁵)Phe or Trp;

A⁷ is Asp, Cys, D-Cys, Dab, Dap, Glu, Lys, Orn, Pen or D-Pen;

R¹ is H, (C₁-C₁₀)alkyl or substituted (C₁-C₁₀)alkyl;

R² and R³ each is, independently, H, (C₁-C₁₀)alkyl, (C₁-C₁₀)heteroalkyl, aryl(C₁-C₅)alkyl, substituted (C₁-C₁₀)alkyl, substituted (C₁-C₁₀)heteroalkyl or substituted aryl(C₁-C₅)alkyl or R² and R³ may be fused together form a cyclic moiety;

R⁴ is CO₂H or C(O)NH₂;

R⁵ and R⁶ each is, independently, H, (C₁-C₁₀)alkyl, (C₁-C₁₀)heteroalkyl, aryl(C₁-C₅)alkyl, substituted (C₁-C₁₀)alkyl, substituted (C₁-C₁₀)heteroalkyl or substituted aryl(C₁-C₅)alkyl or R⁵ and R⁶ may be fused together form a cyclic moiety;

R⁷ and R⁸ each is, independently, H, (C₁-C₁₀)alkyl, (C₁-C₁₀)heteroalkyl, aryl(C₁-C₅)alkyl, substituted (C₁-C₁₀)alkyl, substituted (C₁-C₁₀)heteroalkyl or substituted aryl(C₁-C₅)alkyl; or R⁷ and R⁸ may be fused together form a cyclic moiety;

R⁹ is H, (C₁-C₁₀)alkyl or substituted (C₁-C₁₀)alkyl; and

n is, independently for each occurrence thereof, 1, 2, 3, 4, 5, 6 or 7;

or a pharmaceutically acceptable salt thereof.

A preferred class of compounds according to Formula (VI) useful to treat insulin resistance in a mammalian subject, with or without weight loss, are those compounds wherein:

A¹ is Cys;

A² is D-Ala, Asn, Asp, Gln, Glu or D-Phe;

A³ is His;

A⁴ is D-2-Nal or D-Phe;

A⁵ is Arg;

A⁶ is Trp; and

A⁷ is Cys or Pen;

each of R¹, R², R³, and R⁹ is, independently, H;

R⁴ is C(O)NH₂;

each of R⁵ and R⁶ is, independently, H, (C₁-C₁₀)alkyl, (C₁-C₁₀)heteroalkyl, substituted (C₁-C₁₀)alkyl or substituted (C₁-C₁₀)heteroalkyl or R⁵ and R⁶ may be fused together form a cyclic moiety; and

each of R⁷ and R⁸ is, independently, H, (C₁-C₁₀)alkyl, (C₁-C₁₀)heteroalkyl, substituted (C₁-C₁₀)alkyl or substituted (C₁-C₁₀)heteroalkyl;

or pharmaceutically acceptable salts thereof.

Preferred compounds of the immediately foregoing formula (Formula (VI)) useful to treat insulin resistance in a mammalian subject, with or without weight loss, include:

(SEQ ID NO: 278) Hydantoin(C(O)-(Arg-Gly))-c(Cys-Glu-His-D-Phe-Arg-Trp-Cys)-NH₂; (SEQ ID NO: 278) Hydantoin(C(O)-(Nle-Gly))-c(Cys-Glu-His-D-Phe-Arg-Trp-Cys)-NH₂; (SEQ ID NO: 278) Hydantoin(C(O)-(Gly-Gly))-c(Cys-Glu-His-D-Phe-Arg-Trp-Cys)-NH₂; (SEQ ID NO: 279) Hydantoin(C(O)-(Nle-Gly))-c(Cys-D-Ala-His-D-Phe-Arg-Trp-Cys)-NH₂; (SEQ ID NO: 279) Hydantoin(C(O)-(Gly-Gly))-c(Cys-D-Ala-His-D-Phe-Arg-Trp-Cys)-NH₂; (SEQ ID NO: 280) Hydantoin(C(O)-(Nle-Gly))-c(Cys-D-Ala-His-D-Phe-Arg-Trp-Pen)-NH₂; (SEQ ID NO: 280) Hydantoin(C(O)-(Gly-Gly))-c(Cys-D-Ala-His-D-Phe-Arg-Trp-Pen)-NH₂; (SEQ ID NO: 279) Hydantoin(C(O)-(Ala-Gly))-c(Cys-D-Ala-His-D-Phe-Arg-Trp-Cys)-NH₂; (SEQ ID NO: 279) Hydantoin(C(O)-(D-Ala-Gly))-c(Cys-D-Ala-His-D-Phe-Arg-Trp-Cys)-NH₂; (SEQ ID NO: 279) Hydantoin(C(O)-(Aib-Gly))-c(Cys-D-Ala-His-D-Phe-Arg-Trp-Cys)-NH₂; (SEQ ID NO: 279) Hydantoin(C(O)-(Val-Gly))-c(Cys-D-Ala-His-D-Phe-Arg-Trp-Cys)-NH₂; (SEQ ID NO: 279) Hydantoin(C(O)-(Ile-Gly))-c(Cys-D-Ala-His-D-Phe-Arg-Trp-Cys)-NH₂; (SEQ ID NO: 279) Hydantoin(C(O)-(Leu-Gly))-c(Cys-D-Ala-His-D-Phe-Arg-Trp-Cys)-NH₂; (SEQ ID NO: 281) Hydantoin(C(O)-(Gly-Gly))-c(Cys-Glu-His-D-2-Nal-Arg-Trp-Cys)-NH₂; (SEQ ID NO: 281) Hydantoin(C(O)-(Nle-Gly))-c(Cys-Glu-His-D-2-Nal-Arg-Trp-Cys)-NH₂; (SEQ ID NO: 278) Hydantoin(C(O)-(D-Arg-Gly))-c(Cys-Glu-His-D-Phe-Arg-Trp-Cys)-NH₂; (SEQ ID NO: 278) Hydantoin(C(O)-(Arg-Gly))-c(Cys-Glu-His-D-Phe-Arg-Trp-Cys)-NH₂; (SEQ ID NO: 279) Hydantoin(C(O)-(D-Arg-Gly))-c(Cys-D-Ala-His-D-Phe-Arg-Trp-Cys)-NH₂; (SEQ ID NO: 279) Hydantoin(C(O)-(Arg-Gly))-c(Cys-D-Ala-His-D-Phe-Arg-Trp-Cys)-NH₂; (SEQ ID NO: 282) Hydantoin(C(O)-(D-Arg-Gly))-c(Cys-D-Ala-His-D-2-Nal-Arg-Trp-Cys)-NH₂; (SEQ ID NO: 282) Hydantoin(C(O)-(Arg-Gly))-c(Cys-D-Ala-His-D-2-Nal-Arg-Trp-Cys)-NH₂; (SEQ ID NO: 278) Hydantoin(C(O)-(Nle-Gly))-c(Cys-Glu-His-D-Phe-Arg-Trp-Cys)-NH₂; (SEQ ID NO: 278) Hydantoin(C(O)-(Gly-Gly))-c(Cys-Glu-His-D-Phe-Arg-Trp-Cys)-NH₂; (SEQ ID NO: 279) Hydantoin(C(O)-(Nle-Gly))-c(Cys-D-Ala-His-D-Phe-Arg-Trp-Cys)-NH₂; (SEQ ID NO: 279) Hydantoin(C(O)-(Gly-Gly))-c(Cys-D-Ala-His-D-Phe-Arg-Trp-Cys)-NH₂; (SEQ ID NO: 280) Hydantoin(C(O)-(Nle-Gly))-c(Cys-D-Ala-His-D-Phe-Arg-Trp-Pen)-NH₂; (SEQ ID NO: 280) Hydantoin(C(O)-(Gly-Gly))-c(Cys-D-Ala-His-D-Phe-Arg-Trp-Pen)-NH₂; (SEQ ID NO: 279) Hydantoin(C(O)-(Ala-Gly))-c(Cys-D-Ala-His-D-Phe-Arg-Trp-Cys)-NH₂; (SEQ ID NO: 279) Hydantoin(C(O)-(D-Ala-Gly))-c(Cys-D-Ala-His-D-Phe-Arg-Trp-Cys)-NH₂; (SEQ ID NO: 279) Hydantoin(C(O)-(Aib-Gly))-c(Cys-D-Ala-His-D-Phe-Arg-Trp-Cys)-NH₂; (SEQ ID NO: 279) Hydantoin(C(O)-(Val-Gly))-c(Cys-D-Ala-His-D-Phe-Arg-Trp-Cys)-NH₂; (SEQ ID NO: 279) Hydantoin(C(O)-(Ile-Gly))-c(Cys-D-Ala-His-D-Phe-Arg-Trp-Cys)-NH₂; (SEQ ID NO: 279) Hydantoin(C(O)-(Leu-Gly))-c(Cys-D-Ala-His-D-Phe-Arg-Trp-Cys)-NH₂; (SEQ ID NO: 278) Hydantoin(C(O)-(D-Arg-Gly))-c(Cys-Glu-His-D-Phe-Arg-Trp-Cys)-NH₂; (SEQ ID NO: 278) Hydantoin(C(O)-(Arg-Gly))-c(Cys-Glu-His-D-Phe-Arg-Trp-Cys)-NH₂; (SEQ ID NO: 279) Hydantoin(C(O)-(Arg-Gly))-c(Cys-D-Ala-His-D-Phe-Arg-Trp-Cys)-NH₂; or (SEQ ID NO: 279) Hydantoin(C(O)-(D-Arg-Gly))-c(Cys-D-Ala-His-D-Phe-Arg-Trp-Cys)-NH₂; (SEQ ID NO: 283) Hydantoin(C(O)-(Ala-Nle))-c(Cys-Glu-His-D-Phe-Arg-Trp-Cys)-NH₂; (SEQ ID NO: 283) Hydantoin(C(O)-(Val-Nle))-c(Cys-Glu-His-D-Phe-Arg-Trp-Cys)-NH₂; (SEQ ID NO: 283) Hydantoin(C(O)-(Gly-Nle))-c(Cys-Glu-His-D-Phe-Arg-Trp-Cys)-NH₂; (SEQ ID NO: 284) Hydantoin(C(O)-(A6c-Nle))-c(Cys-D-Ala-His-D-Phe-Arg-Trp-Cys)-NH₂; (SEQ ID NO: 284) Hydantoin(C(O)-(Gly-Nle))-c(Cys-D-Ala-His-D-Phe-Arg-Trp-Cys)-NH₂; (SEQ ID NO: 284) Hydantoin(C(O)-(Ala-Nle))-c(Cys-D-Ala-His-D-Phe-Arg-Trp-Cys)-NH₂; (SEQ ID NO: 284) Hydantoin(C(O)-(D-Ala-Nle))-c(Cys-D-Ala-His-D-Phe-Arg-Trp-Cys)-NH₂; (SEQ ID NO: 284) Hydantoin(C(O)-(Val-Nle))-c(Cys-D-Ala-His-D-Phe-Arg-Trp-Cys)-NH₂; (SEQ ID NO: 284) Hydantoin(C(O)-(Leu-Nle))-c(Cys-D-Ala-His-D-Phe-Arg-Trp-Cys)-NH₂; (SEQ ID NO: 284) Hydantoin(C(O)-(Cha-Nle))-c(Cys-D-Ala-His-D-Phe-Arg-Trp-Cys)-NH₂; or (SEQ ID NO: 284) Hydantoin(C(O)-(Aib-Nle))-c(Cys-D-Ala-His-D-Phe-Arg-Trp-Cys)-NH₂; (SEQ ID NO: 285) Hydantoin(C(O)-(Gly-Arg))-c(Cys-Glu-His-D-Phe-Arg-Trp-Cys)-NH₂; (SEQ ID NO: 285) Hydantoin(C(O)-(Gly-Arg))-c(Cys-Glu-His-D-2-Nal-Arg-Trp-Cys)-NH₂; (SEQ ID NO: 286) Hydantoin(C(O)-(Gly-Arg))-c(Cys-D-Ala-His-D-Phe-Arg-Trp-Cys)-NH₂; (SEQ ID NO: 286) Hydantoin(C(O)-(Gly-Arg))-c(Cys-D-Ala-His-D-2-Nal-Arg-Trp-Cys)-NH₂; (SEQ ID NO: 287) Hydantoin(C(O)-(Gly-D-Arg))-c(Cys-Glu-His-D-Phe-Arg-Trp-Cys)-NH₂; (SEQ ID NO: 287) Hydantoin(C(O)-(Gly-D-Arg))-c(Cys-Glu-His-D-Phe-Arg-Trp-Cys)-NH₂; (SEQ ID NO: 288) Hydantoin(C(O)-(Gly-D-Arg))-c(Cys-D-Ala-His-D-Phe-Arg-Trp-Cys)-NH₂; and (SEQ ID NO: 288) Hydantoin(C(O)-(Gly-D-Arg))-c(Cys-D-Ala-His-D-2-Nal-Arg-Trp-Cys)-NH₂; (SEQ ID NO: 289) Hydantoin(C(O)-(Nle-Ala))-c(Cys-Glu-His-D-Phe-Arg-Trp-Cys)-NH₂; or pharmaceutically acceptable salts thereof.

In a seventh embodiment, the invention provides a method to treat insulin resistance in a mammalian subject, with or without weight loss, by the administration of a therapeutically effective amount of a melanocortin receptor ligand belonging to a class of cyclic peptide analogs that are ligands for the melanocortin receptors having a structure according to Formula (VII) as depicted below (see International Patent Application Number PCT/US08/06675 which is incorporated herein by reference in its entirety):

wherein

X is selected from the group consisting of —CH₂—S—S—CH₂—, —C(CH₃)₂—S—S—CH₂—, —CH₂—S—S—C(CH₃)₂—, —C(CH₃)₂—S—S—C(CH₃)₂—, —(CH₂)₂—S—S—CH₂—, —CH₂—S—S—(CH₂)₂, —(CH₂)₂—S—S—(CH₂)₂—, —C(CH₃)₂—S—S—(CH₂)₂—, —(CH₂)₂—S—S—C (CH₃)₂—, —(CH₂)_(t)—(C(O)—NR⁸—(CH₂)_(r) and —(CH₂)_(r)—NR⁸—C(O)—(CH₂)_(t)—;

each of R¹ and R⁵ is, independently, H, (C₁-C₁₀)alkyl or substituted (C₁-C₁₀)alkyl;

each of R² and R³ is, independently, H, (C₁-C₁₀)alkyl, (C₁-C₁₀)heteroalkyl, aryl(C₁-C₅)alkyl, substituted (C₁-C₁₀)alkyl, substituted (C₁-C₁₀)heteroalkyl or substituted aryl(C₁-C₅)alkyl or R² and R³ may be fused together to form a ring;

R⁴ is OH or NH₂;

each of R⁶ and R⁷ is, independently, H, (C₁-C₁₀)alkyl or substituted (C₁-C₁₀)alkyl;

A¹ is an L- or D-amino acid or deleted;

A² is His, 2-Pal, 3-Pal, 4-Pal, (X¹,X²,X³,X⁴,X⁵)Phe, Taz, 2-Thi or 3-Thi;

A³ is D-Bal, D-1-Nal, D-2-Nal, D-Phe or D-(X¹,X²,X³,X⁴,X⁵)Phe;

A⁴ is Arg, hArg, Dab, Dap, Lys or Orn;

A⁵ is Bal, 1-Nal, 2-Nal, (X¹,X²,X³,X⁴,X⁵)Phe or Trp;

r is, independently for each occurrence thereof, 1, 2, 3, 4 or 5; and

t is, independently for each occurrence thereof, 1 or 2;

or pharmaceutically acceptable salts thereof.

In the preferred aspect of the compounds according to Formula (VII) useful to treat insulin resistance in a mammalian subject, with or without weight loss,

A¹ is Ala, D-Ala, Asn, Asp, Gln, Glu or Gly;

or pharmaceutically acceptable salts thereof.

Preferred compounds according to Formula (VII) useful in the treatment of insulin resistance in a mammalian subject, include the following compounds:

(SEQ ID NO: 290) c[Hydantoin(C(O)-(Nle-Cys))-D-Ala-His-D-Phe-Arg- Trp-Cys]-NH₂; (SEQ ID NO: 290) c[Hydantoin(C(O)-(Ala-Cys))-D-Ala-His-D-Phe-Arg- Trp-Cys]-NH₂; (SEQ ID NO: 290) c[Hydantoin(C(O)-(D-Ala-Cys))-D-Ala-His-D-Phe-Arg- Trp-Cys]-NH₂; (SEQ ID NO: 290) c[Hydantoin(C(O)-(Aib-Cys))-D-Ala-His-D-Phe-Arg- Trp-Cys]-NH₂; (SEQ ID NO: 290) c[Hydantoin(C(O)-(Val-Cys))-D-Ala-His-D-Phe-Arg- Trp-Cys]-NH₂; (SEQ ID NO: 290) c[Hydantoin(C(O)-(Abu-Cys))-D-Ala-His-D-Phe-Arg- Trp-Cys]-NH₂; (SEQ ID NO: 290) c[Hydantoin(C(O)-(Leu-Cys))-D-Ala-His-D-Phe-Arg- Trp-Cys]-NH₂; (SEQ ID NO: 290) c[Hydantoin(C(O)-(Ile-Cys))-D-Ala-His-D-Phe-Arg- Trp-Cys]-NH₂; (SEQ ID NO: 290) c[Hydantoin(C(O)-(Cha-Cys))-D-Ala-His-D-Phe-Arg- Trp-Cys]-NH₂; (SEQ ID NO: 290) c[Hydantoin(C(O)-(A6c-Cys))-D-Ala-His-D-Phe-Arg- Trp-Cys]-NH₂; (SEQ ID NO: 290) c[Hydantoin(C(O)-(Phe-Cys))-D-Ala-His-D-Phe-Arg- Trp-Cys]-NH₂; (SEQ ID NO: 290) c[Hydantoin(C(O)-(Gly-Cys))-D-Ala-His-D-Phe-Arg- Trp-Cys]-NH₂; or (SEQ ID NO: 291) c[Hydantoin(C(O)-(Gly-Cys))-Glu-His-D-Phe-Arg- Trp-Cys]-NH₂; or (SEQ ID NO: 291) c[Hydantoin(C(O)-(Gly-Cys))-Glu-His-D-Phe-Arg- Trp-Cys]-NH₂; or pharmaceutically acceptable salts thereof.

In an eighth embodiment, the present invention is directed to a method to treat insulin resistance in a mammalian subject, with or without weight loss, by the administration of a therapeutically effective amount of a melanocortin receptor ligand according to Formula (VIII) (see International Patent Application Number PCT/US08/07411, incorporated herein by reference in its entirety):

(R²R³)-A⁰-A¹-c(A²-A³-A⁴-A⁵-A⁶-A⁷-A⁸-A⁹)-A¹⁰-R¹   (VIII)

wherein:

A⁰ is an aromatic amino acid

A¹ is Acc, HN—(CH₂)_(m)(C(O), an L- or D-amino acid;

A² is Asp, Cys, D-Cys, hCys, D-hCys, Glu, Pen, or D-Pen;

A³ is Aib, Ala, β-Ala, Gaba, Gly or a D-amino acid;

A⁴ is His, 2-Pal, 3-Pal, 4-Pal, (X¹,X²,X³,X⁴,X⁵)Phe, Taz, 2-Thi, or 3-Thi;

A⁵ is D-Bal, D-1-Nal, D-2-Nal, D-Phe, L-Phe, D-(X¹,X²,X³,X⁴,X⁵)Phe, L-Phe, D-Trp or D-(Et)Tyr;

A⁶ is Arg, hArg, Dab, Dap, Lys, Orn, or HN—CH((CH₂)_(n)—N(R⁴R⁵))—(C(O);

A⁷ is Bal, D-Bal, Bip, D-Bip, 1-Nal, D-1-Nal, 2-Nal, D-2-Nal, or D-Trp;

A⁸ is Acc, Aha, Ahx, Ala, D-Ala, β-Ala, Apn, Gaba, Gly, HN—(CH₂)_(s)—(C(O), or deleted;

A⁹ is Cys, D-Cys, hCys, D-hCys, Dab, Dap, Lys, Orn, Pen, or D-Pen;

A¹⁰ is Acc, HN—(CH₂)_(t)—(C(O), L- or D-amino acid, or deleted;

R¹ is OH, or NH₂;

each of R² and R³ is, independently for each occurrence selected from the group consisting of H, (C₁-C₃₀)alkyl, (C₁-C₃₀)heteroalkyl, (C₁-C₃₀)acyl, (C₂-C₃₀)alkenyl, (C₂-C₃₀)alkynyl, aryl(C₁-C₃₀)alkyl, aryl(C₁-C₃₀)acyl, substituted (C₁-C₃₀)alkyl, substituted (C₁-C₃₀)heteroalkyl, substituted (C₁-C₃₀)acyl, substituted (C₂-C₃₀)alkenyl, substituted (C₂-C₃₀)alkynyl, substituted aryl(C₁-C₃₀)alkyl, and substituted aryl(C₁-C₃₀)acyl;

each of R⁴ and R⁵ is, independently for each occurrence, H, (C₁-C₄₀)alkyl, (C₁-C₄₀)heteroalkyl, (C₁-C₄₀)acyl, (C₂-C₄₀)alkenyl, (C₂-C₄₀)alkynyl, aryl(C₁-C₄₀)alkyl, aryl(C₁-C₄₀)acyl, substituted (C₁-C₄₀)alkyl, substituted (C₁-C₄₀)heteroalkyl, substituted (C₁-C₄₀)acyl, substituted (C₂-C₄₀)alkenyl, substituted (C₂-C₄₀)alkynyl, substituted aryl(C₁-C₄₀)alkyl, substituted aryl(C₁-C₄₀)acyl, (C₁-C₄₀)alkylsulfonyl, or —C(NH)—NH₂;

m is, independently for each occurrence, 1, 2, 3, 4, 5, 6 or 7;

n is, independently for each occurrence, 1, 2, 3, 4 or 5;

s is, independently for each occurrence, 1, 2, 3, 4, 5, 6, or 7;

t is, independently for each occurrence, 1, 2, 3, 4, 5, 6, or 7;

X¹, X², X³, X⁴, and X⁵ each is, independently for each occurrence, H, F, Cl, Br, I, (C₁₋₁₀)alkyl, substituted (C₁₋₁₀)alkyl, (C₂₋₁₀)alkenyl, substituted (C₂₋₁₀)alkenyl, (C₂₋₁₀)alkynyl, substituted (C₂₋₁₀)alkynyl, aryl, substituted aryl, OH, NH₂, NO₂, or CN; provided that

(I). when R⁴ is (C₁-C₄₀)acyl, aryl(C₁-C₄₀)acyl, substituted (C₁-C₄₀)acyl,

substituted aryl(C₁-C₄₀)acyl, (C₁-C₄₀)alkylsulfonyl, or —C(NH)—NH₂, then R⁵ is H or (C₁-C₄₀)alkyl, (C₁-C₄₀)heteroalkyl, (C₂-C₄₀)alkenyl, (C₂-C₄₀)alkynyl, aryl(C₁-C₄₀)alkyl, substituted (C₁-C₄₀)alkyl, substituted (C₁-C₄₀)heteroalkyl, substituted (C₂-C₄₀)alkenyl, substituted (C₂-C₄₀)alkynyl, or substituted aryl(C₁-C₄₀)alkyl;

(II). when R² is (C₁-C₃₀)acyl, aryl(C₁-C₃₀)acyl, substituted (C₁-C₃₀)acyl, or substituted aryl(C₁-C₃₀)acyl, then R³ is H, (C₁-C₃₀)alkyl, (C₁-C₃₀)heteroalkyl, (C₂-C₃₀)alkenyl, (C₂-C₃₀)alkynyl, aryl(C₁-C₃₀)alkyl, substituted (C₁-C₃₀)alkyl, substituted (C₁-C₃₀)heteroalkyl, substituted (C₂-C₃₀)alkenyl, substituted (C₂-C₃₀)alkynyl, or substituted aryl(C₁-C₃₀)alkyl;

(III). when A² is Cys, D-Cys, hCys, D-hCys, Pen, or D-Pen, then A⁹ is Cys, D-Cys, hCys, D-hCys, Pen, or D-Pen;

(IV). when A² is Asp or Glu, then A⁹ is Dab, Dap, Orn, or Lys;

(V). when A⁸ is Ala or Gly, then A¹ is not Nle; or

pharmaceutically acceptable salts thereof.

A preferred group of compounds of the immediate foregoing formula useful to treat insulin resistance in a mammalian subject, with or without weight loss, is wherein

A⁰ is 1-Nal, 2-Nal, His, Pff, Phe, Trp, or Tyr;

A¹ is Arg;

A² is Cys;

A³ is D-Ala;

A⁴ is His;

A⁵ is D-Phe

A⁶ is Arg;

A⁷ is Trp

A⁸ is deleted;

A⁹ is Cys; and

A¹⁰ is deleted;

or pharmaceutically acceptable salts thereof.

Preferred compounds of the immediately foregoing group of compounds is which are useful to treat insulin resistance in a mammalian subject, with or without weight loss, of the formula:

(SEQ ID NO: 292) Ac-Tyr-Arg-c(Cys-D-Ala-His-D-Phe-Arg-Trp-Cys)-NH₂; (SEQ ID NO: 292) Ac-2-Nal-Arg-c(Cys-D-Ala-His-D-Phe-Arg-Trp-Cys)- NH₂; (SEQ ID NO: 292) Ac-1-Nal-Arg-c(Cys-D-Ala-His-DPhe-Arg-Trp-Cys)- NH₂; (SEQ ID NO: 292) Ac-Phe-Arg-c(Cys-D-Ala-His-D-Phe-Arg-Trp-Cys)- NH₂; (SEQ ID NO: 292) Ac-Trp-Arg-c(Cys-D-Ala-His-D-Phe-Arg-Trp-Cys)-NH₂; (SEQ ID NO: 292) Ac-Pff-Arg-c(Cys-D-Ala-His-D-Phe-Arg-Trp-Cys)-NH₂; (SEQ ID NO: 293) H-His-Arg-c(Cys-D-Ala-His-D-Phe-Arg-Trp-Cys)-NH₂; or (SEQ ID NO: 292) Ac-His-Arg-c(Cys-D-Ala-His-D-Phe-Arg-Trp-Cys)-NH₂; or pharmaceutically acceptable salts thereof.

In yet another preferred embodiment, the compound or compounds of Formula (I), (II), (III), (IV), (V), (VI), (VII) or (VIII) as defined hereinabove, which are useful to treat insulin resistance in a mammalian subject, with or without weight loss, or a pharmaceutically acceptable salt thereof, are provided to said subject in need in a composition with a pharmaceutically acceptable carrier or diluent.

In preferred embodiment, the invention provides a method of treating insulin resistance in a subject in need thereof, comprising peripheral administration of an effective amount of a melanocortin receptor 4 agonist to treat the insulin resistance in the subject in need thereof.

In one aspect, the melanocortin receptor 4 agonist useful to treat insulin resistance with or without an accompanying reduction in body weight in the subject in need thereof, is selected from the group consisting of:

SEQ ID NO: 1 Ac-Nle-c(Asp-His-D-Phe-Arg-Trp-β-Ala-Lys)-NH₂; SEQ ID NO: 1 Ac-Nle-c(Asp-His-D-Phe-Arg-Trp-A6c-Lys)-NH₂; SEQ ID NO: 2 Ac-Nle-c(Cys-His-D-Phe-Arg-Trp-Ahx-Cys)-NH₂; SEQ ID NO: 3 D-Phe-c(Cys-His-D-Phe-Arg-Trp-Ala-D-Cys)-Thr-NH₂; SEQ ID NO: 3 D-Phe-c(Cys-His-D-Phe-Arg-Trp-β-Ala-D-Cys)-Thr-NH₂; SEQ ID NO: 3 D-Phe-c(Cys-His-D-Phe-Arg-Trp-Gaba-D-Cys)-Thr-NH₂; SEQ ID NO: 2 Ac-Nle-c(Cys-His-D-Phe-Arg-Trp-Apn-Cys)-NH₂; SEQ ID NO: 4 Ac-Nle-c(Asp-His-D-Phe-Arg-Trp-Apn-Lys)-NH₂; SEQ ID NO: 5 Ac-A6c-c(Asp-His-D-Phe-Arg-Trp-Gaba-Lys)-NH₂; SEQ ID NO: 6 Ac-D-2-Nal-c(Asp-His-D-Phe-Arg-Trp-Gaba-Lys)-NH₂; SEQ ID NO: 6 Ac-Cha-c(Asp-His-D-Phe-Arg-Trp-Gaba-Lys)-NH₂; SEQ ID NO: 6 Ac-Nle-c(Asp-His-D-Phe-Arg-Trp-Gaba-Lys)-NH₂; SEQ ID NO: 7 Ac-Nle-c(Cys-D-Ala-His-D-Phe-Arg-Trp-Cys)-NH₂; SEQ ID NO: 7 Ac-Nle-c(Cys-β-Ala-His-D-Phe-Arg-Trp-Cys)-NH₂; SEQ ID NO: 7 Ac-Nle-c(Cys-Gaba-His-D-Phe-Arg-Trp-Cys)-NH₂; SEQ ID NO: 7 Ac-Nle-c(Cys-Aib-His-D-Phe-Arg-Trp-Cys)-NH₂; SEQ ID NO: 7 Ac-Nle-c(Cys-Gly-His-D-Phe-Arg-Trp-Cys)-NH₂; SEQ ID NO: 8 Ac-Nle-c(D-Cys-Ala-His-D-Phe-Arg-Trp-Cys)-NH₂; SEQ ID NO: 8 Ac-Nle-c(D-Cys-D-Ala-His-D-Phe-Arg-Trp-Cys)-NH₂; SEQ ID NO: 8 Ac-Nle-c(D-Cys-β-Ala-His-D-Phe-Arg-Trp-Cys)-NH₂; SEQ ID NO: 8 Ac-Nle-c(D-Cys-Gaba-His-D-Phe-Arg-Trp-Cys)-NH₂; SEQ ID NO: 8 Ac-Nle-c(D-Cys-Aib-His-D-Phe-Arg-Trp-Cys)-NH₂; SEQ ID NO: 8 Ac-Nle-c(D-Cys-Gly-His-D-Phe-Arg-Trp-Cys)-NH₂; SEQ ID NO: 9 Ac-Nle-c(Cys-D-Ala-His-D-Phe-Arg-Trp-D-Cys)-NH₂; SEQ ID NO: 9 Ac-Nle-c(Cys-β-Ala-His-D-Phe-Arg-Trp-D-Cys)-NH₂; SEQ ID NO: 9 Ac-Nle-c(Cys-Gaba-His-D-Phe-Arg-Trp-D-Cys)-NH₂; SEQ ID NO: 9 Ac-Nle-c(Cys-Aib-His-D-Phe-Arg-Trp-D-Cys)-NH₂; SEQ ID NO: 9 Ac-Nle-c(Cys-Gly-His-D-Phe-Arg-Trp-D-Cys)-NH₂; SEQ ID NO: 10 Ac-Nle-c(D-Cys-Ala-His-D-Phe-Arg-Trp-D-Cys)-NH₂; SEQ ID NO: 10 Ac-Nle-c(D-Cys-D-Ala-His-D-Phe-Arg-Trp-D-Cys)-NH₂; SEQ ID NO: 10 Ac-Nle-c(D-Cys-β-Ala-His-D-Phe-Arg-Trp-D-Cys)-NH₂; SEQ ID NO: 10 Ac-Nle-c(D-Cys-Gaba-His-D-Phe-Arg-Trp-D-Cys)-NH₂; SEQ ID NO: 10 Ac-Nle-c(D-Cys-Aib-His-D-Phe-Arg-Trp-D-Cys)-NH₂; SEQ ID NO: 11 Ac-Oic-c(Asp-His-D-Phe-Arg-Trp-Gaba-Lys)-NH₂; SEQ ID NO: 11 Ac-Chg-c(Asp-His-D-Phe-Arg-Trp-Gaba-Lys)-NH₂; SEQ ID NO: 11 Ac-hCha-c(Asp-His-D-Phe-Arg-Trp-Gaba-Lys)-NH₂; SEQ ID NO: 11 Ac-D-Cha-c(Asp-His-D-Phe-Arg-Trp-Gaba-Lys)-NH₂; SEQ ID NO: 11 Ac-Nip-c(Asp-His-D-Phe-Arg-Trp-Gaba-Lys)-NH₂; SEQ ID NO: 11 Ac-hPro-c(Asp-His-D-Phe-Arg-Trp-Gaba-Lys)-NH₂; SEQ ID NO: 11 Ac-hLeu-c(Asp-His-D-Phe-Arg-Trp-Gaba-Lys)-NH₂; SEQ ID NO: 11 Ac-Phe-c(Asp-His-D-Phe-Arg-Trp-Gaba-Lys)-NH₂; SEQ ID NO: 11 Ac-D-Phe-c(Asp-His-D-Phe-Arg-Trp-Gaba-Lys)-NH₂; SEQ ID NO: 11 Ac-D-Chg-c(Asp-His-D-Phe-Arg-Trp-Gaba-Lys)-NH₂; SEQ ID NO: 12 n-butanoyl-Cha-c(Asp-His-D-Phe-Arg-Trp-Gaba-Lys)-NH₂; SEQ ID NO: 11 Ac-hPhe-c(Asp-His-D-Phe-Arg-Trp-Gaba-Lys)-NH₂; SEQ ID NO: 11 Ac-β-hMet-c(Asp-His-D-Phe-Arg-Trp-Gaba-Lys)-NH₂; SEQ ID NO: 11 Ac-Gaba-c(Asp-His-D-Phe-Arg-Trp-Gaba-Lys)-NH₂; SEQ ID NO: 13 Ac-Cha-c(Asp-His-D-Phe-Arg-D-Trp-Ala-Lys)-NH₂; SEQ ID NO: 13 Ac-hCha-c(Asp-His-D-Phe-Arg-D-Trp-Ala-Lys)-NH₂; SEQ ID NO: 13 Ac-Leu-c(Asp-His-D-Phe-Arg-D-Trp-Ala-Lys)-NH₂; SEQ ID NO: 13 Ac-hLeu-c(Asp-His-D-Phe-Arg-D-Trp-Ala-Lys)-NH₂; SEQ ID NO: 13 Ac-Phe-c(Asp-His-D-Phe-Arg-D-Trp-Ala-Lys)-NH₂; SEQ ID NO: 14 Ac-Nle-c(Asp-His-D-Phe-Arg-D-Trp-D-Ala-Lys)-NH₂; SEQ ID NO: 14 Ac-Nle-c(Asp-His-D-Phe-Arg-D-Trp-β-Ala-Lys)-NH₂; SEQ ID NO: 14 Ac-Nle-c(Asp-His-D-Phe-Arg-D-Trp-Gaba-Lys)-NH₂; SEQ ID NO: 14 Ac-Nle-c(Asp-His-D-Phe-Arg-D-Trp-Aha-Lys)-NH₂; SEQ ID NO: 14 Ac-Nle-c(Asp-His-D-Phe-Arg-D-Trp-Apn-Lys)-NH₂; SEQ ID NO: 15 Ac-Nle-c(Cys-His-D-Phe-Arg-D-Trp-Apn-Cys)-NH₂; SEQ ID NO: 15 Ac-Nle-c(Cys-His-D-Phe-Arg-D-Trp-Gaba-Cys)-NH₂; SEQ ID NO: 15 Ac-Nle-c(Cys-His-D-Phe-Arg-D-Trp-Ahx-Cys)-NH₂; SEQ ID NO: 15 Ac-Nle-c(Cys-His-D-Phe-Arg-D-Trp-β-Ala-Cys)-NH₂; SEQ ID NO: 15 Ac-Nle-c(Cys-His-D-Phe-Arg-D-Trp-D-Ala-Cys)-NH₂; SEQ ID NO: 16 Ac-Nle-c(Cys-D-Ala-His-D-2-Nal-Arg-Trp-Cys)-NH₂; SEQ ID NO: 16 Ac-Nle-c(Cys-D-Ala-His-D-2-Nal-Arg-2-Nal-Cys)-NH₂; SEQ ID NO: 16 Ac-Nle-c(Cys-D-Ala-His-D-2-Nal-Arg-1-Nal-Cys)-NH₂; SEQ ID NO: 17 n-butanoyl-Nle-c(Cys-D-Ala-His-D-Phe-Arg-2-Nal-Cys)-NH₂; SEQ ID NO: 17 n-butanoyl-Nle-c(Cys-D-Ala-His-D-Phe-Arg-Trp-Cys)-NH₂; SEQ ID NO: 18 Ac-Nle-c(Cys-D-Ala-His-D-Phe-Arg-2-Nal-Cys)-NH₂; SEQ ID NO: 18 Ac-Nle-c(Cys-D-Ala-His-D-Phe-Arg-1-Nal-Cys)-NH₂; SEQ ID NO: 18 Ac-Nle-c(Cys-D-Ala-His-D-Phe-Arg-Bal-Cys)-NH₂; SEQ ID NO: 61 Ac-Nle-c(Cys-D-Glu-His-D-Phe-Arg-Trp-Cys)-NH₂; SEQ ID NO: 19 Ac-Nle-c(Asp-His-D-Phe-Arg-Trp-D-Ala-Lys)-NH₂; SEQ ID NO: 20 Ac-Nle-c(Cys-D-Ala-His-D-2-Nal-Arg-Bal-Cys)-NH₂; SEQ ID NO: 21 Ac-Nle-c(Pen-D-Ala-His-D-Phe-Arg-Trp-Cys)-NH₂; SEQ ID NO: 22 Ac-Nle-c(Cys-D-Ala-His-D-Phe-Arg-Trp-Pen)-NH₂; SEQ ID NO: 22 Ac-Nle-c(Pen-D-Ala-His-D-Phe-Arg-Trp-Pen)-NH₂; SEQ ID NO: 23 D-Phe-c(Cys-His-D-Phe-hArg-Trp-β-Ala-D-Cys)-Thr-NH₂; SEQ ID NO: 24 D-Phe-c(Cys-His-D-(Et)Tyr-Arg-Trp-β-Ala-D-Cys)-Thr-NH₂; SEQ ID NO: 25 D-Phe-c(Cys-His-D-Phe-Arg-Bip-β-Ala-D-Cys)-Thr-NH₂; SEQ ID NO: 24 D-Phe-c(Cys-His-D-(Et)Tyr-hArg-Trp-β-Ala-D-Cys)-Thr-NH₂; SEQ ID NO: 26 D-Phe-c(Cys-His-D-Phe-hArg-Bip-β-Ala-D-Cys)-Thr-NH₂; SEQ ID NO: 26 D-Phe-c(Cys-His-D-(Et)Tyr-hArg-Bip-β-Ala-D-Cys)-Thr-NH₂; SEQ ID NO: 27 Nle-c(Cys-His-D-Phe-Arg-Trp-Apn-Cys)-NH₂; SEQ ID NO: 28 Ac-Nle-c(Asp-D-Ala-His-D-Phe-Arg-Trp-Lys)-NH₂; SEQ ID NO: 28 Ac-Nle-c(Asp-D-Ala-His-D-Phe-Arg-Bal-Lys)-NH₂; SEQ ID NO: 29 Ac-Nle-c(Cys-D-Ala-His-D-Phe-Arg-Trp-Pen)-OH; SEQ ID NO: 30 Ac-Nle-c(Cys-D-Abu-His-D-Phe-Arg-Trp-Cys)-NH₂; SEQ ID NO: 30 Ac-Nle-c(Cys-D-Val-His-D-Phe-Arg-Trp-Cys)-NH₂; SEQ ID NO: 30 Ac-Nle-c(Cys-D-Ile-His-D-Phe-Arg-Trp-Cys)-NH₂; SEQ ID NO: 30 Ac-Nle-c(Cys-D-Leu-His-D-Phe-Arg-Trp-Cys)-NH₂; SEQ ID NO: 30 Ac-Nle-c(Cys-D-Tle-His-D-Phe-Arg-Trp-Cys)-NH₂; SEQ ID NO: 30 Ac-Nle-c(Cys-D-Cha-His-D-Phe-Arg-Trp-Cys)-NH₂; SEQ ID NO: 31 Ac-Nle-c(Pen-His-D-Phe-Arg-Trp-Gaba-Cys)-NH₂; SEQ ID NO: 32 Ac-Nle-c(Cys-His-D-Phe-Arg-Trp-Gaba-Pen)-NH₂; SEQ ID NO: 32 Ac-Nle-c(Pen-His-D-Phe-Arg-Trp-Gaba-Pen)-NH₂; SEQ ID NO: 33 Ac-Leu-c(Cys-His-D-Phe-Arg-Trp-Gaba-Cys)-NH₂; SEQ ID NO: 33 Ac-Cha-c(Cys-His-D-Phe-Arg-Trp-Gaba-Cys)-NH₂; SEQ ID NO: 33 Ac-Ile-c(Cys-His-D-Phe-Arg-Trp-Gaba-Cys)-NH₂; SEQ ID NO: 33 Ac-Phe-c(Cys-His-D-Phe-Arg-Trp-Gaba-Cys)-NH₂; SEQ ID NO: 33 Ac-Val-c(Cys-His-D-Phe-Arg-Trp-Gaba-Cys)-NH₂; SEQ ID NO: 33 Ac-2-Nal-c(Cys-His-D-Phe-Arg-Trp-Gaba-Cys)-NH₂; SEQ ID NO: 34 Nle-c(Cys-His-D-Phe-Arg-Trp-Gaba-Cys)-NH₂; SEQ ID NO: 34 Phe-c(Cys-His-D-Phe-Arg-Trp-Gaba-Cys)-NH₂; SEQ ID NO: 35 Ac-Nle-c(Cys-3-Pal-D-Phe-Arg-Trp-Gaba-Cys)-NH₂; SEQ ID NO: 36 Ac-Nle-c(Cys-D-Ala-His-D-Phe-Arg-Trp-Cys)-OH; SEQ ID NO: 37 Ac-Nle-c(Cys-His-Phe-Arg-D-Trp-Gaba-Cys)-NH₂; SEQ ID NO: 38 Ac-Nle-c(Asp-His-D-2-Nal-Arg-Trp-Ala-Lys)-NH₂; SEQ ID NO: 38 Ac-Nle-c(Asp-His-D-2-Nal-Arg-Trp-β-Ala-Lys)-NH₂; SEQ ID NO: 39 Ac-Nle-c(Cys-His-D-2-Nal-Arg-Trp-Gaba-Cys)-NH₂; SEQ ID NO: 39 Ac-Nle-c(Cys-His-D-2-Nal-Arg-Trp-Ahx-Cys)-NH₂; SEQ ID NO: 40 Ac-hPhe-c(Asp-His-D-2-Nal-Arg-Trp-Gaba-Lys)-NH₂; SEQ ID NO: 40 Ac-Cha-c(Asp-His-D-2-Nal-Arg-Trp-Gaba-Lys)-NH₂; SEQ ID NO: 41 Ac-Nle-c(Asp-His-D-Phe-Arg-Trp-β-Ala-Lys)-OH; SEQ ID NO: 42 Ac-Nle-c(Cys-His-D-Phe-Arg-Trp-Ahx-Cys)-OH; SEQ ID NO: 43 D-Phe-c(Cys-His-D-Phe-Arg-Trp-Ala-D-Cys)-Thr-OH; SEQ ID NO: 43 D-Phe-c(Cys-His-D-Phe-Arg-Trp-β-Ala-D-Cys)-Thr-OH; SEQ ID NO: 43 D-Phe-c(Cys-His-D-Phe-Arg-Trp-Gaba-D-Cys)-Thr-OH; SEQ ID NO: 42 Ac-Nle-c(Cys-His-D-Phe-Arg-Trp-Apn-Cys)-OH; SEQ ID NO: 41 Ac-Nle-c(Asp-His-D-Phe-Arg-Trp-Apn-Lys)-OH; SEQ ID NO: 44 Ac-Cha-c(Asp-His-D-Phe-Arg-Trp-Gaba-Lys)-OH; SEQ ID NO: 44 Ac-Nle-c(Asp-His-D-Phe-Arg-Trp-Gaba-Lys)-OH; SEQ ID NO: 44 Ac-Chg-c(Asp-His-D-Phe-Arg-Trp-Gaba-Lys)-OH; SEQ ID NO: 44 Ac-D-Cha-c(Asp-His-D-Phe-Arg-Trp-Gaba-Lys)-OH; SEQ ID NO: 44 Ac-hCha-c(Asp-His-D-Phe-Arg-Trp-Gaba-Lys)-OH; SEQ ID NO: 44 Ac-D-Chg-c(Asp-His-D-Phe-Arg-Trp-Gaba-Lys)-OH; SEQ ID NO: 44 Ac-hPhe-c(Asp-His-D-Phe-Arg-Trp-Gaba-Lys)-OH; SEQ ID NO: 45 Ac-Nle-c(Cys-His-D-Phe-Arg-D-Trp-Gaba-Cys)-OH; SEQ ID NO: 45 Ac-Nle-c(Cys-His-D-Phe-Arg-D-Trp-Ahx-Cys)-OH; SEQ ID NO: 45 Ac-Nle-c(Cys-His-D-Phe-Arg-D-Trp-β-Ala-Cys)-OH; SEQ ID NO: 45 Ac-Nle-c(Cys-His-D-Phe-Arg-D-Trp-D-Ala-Cys)-OH; SEQ ID NO: 46 Ac-Nle-c(Cys-D-Ala-His-D-2-Nal-Arg-Trp-Cys)-OH; SEQ ID NO: 46 Ac-Nle-c(Cys-D-Ala-His-D-2-Nal-Arg-2-Nal-Cys)-OH; SEQ ID NO: 46 Ac-Nle-c(Cys-D-Ala-His-D-2-Nal-Arg-1-Nal-Cys)-OH; SEQ ID NO: 46 Ac-Nle-c(Cys-D-Ala-His-D-2-Nal-Arg-Bal-Cys)-OH; SEQ ID NO: 47 Ac-Nle-c(Pen-D-Ala-His-D-Phe-Arg-Trp-Cys)-OH; SEQ ID NO: 48 Ac-Nle-c(Cys-His-D-Phe-Arg-Trp-Gaba-Pen)-OH; SEQ ID NO: 49 Ac-Arg-c(Cys-D-Ala-His-D-2-Nal-Arg-Trp-Cys)-NH₂; SEQ ID NO: 50 Ac-Arg-c(Cys-D-Ala-His-D-Phe-Arg-Trp-Cys)-NH₂; SEQ ID NO: 50 Ac-D-Arg-c(Cys-D-Ala-His-D-Phe-Arg-Trp-Cys)-NH₂; SEQ ID NO: 51 Ac-D-Arg-c(Cys-D-Ala-His-D-Phe-Arg-Trp-Pen)-NH₂; SEQ ID NO: 52 Ac-D-Arg-c(Cys-His-D-Phe-Arg-Trp-Gaba-Pen)-NH₂; SEQ ID NO: 52 Ac-Arg-c(Cys-His-D-Phe-Arg-Trp-Gaba-Pen)-NH₂; SEQ ID NO: 51 Ac-Arg-c(Cys-D-Ala-His-D-Phe-Arg-Trp-Pen)-NH₂; SEQ ID NO: 53 Ac-D-Arg-c(Asp-His-D-Phe-Arg-Trp-Ala-Lys)-NH₂; SEQ ID NO: 53 Ac-Arg-c(Asp-His-D-Phe-Arg-Trp-Ala-Lys)-NH₂; SEQ ID NO: 35 Ac-Nle-c(Cys-3-Pal-D-Phe-Arg-Trp-Gaba-Cys)-NH₂; SEQ ID NO: 54 Ac-Nle-c(Cys-D-Ala-His-D-Phe-Arg-Trp-Gly-Cys)-NH₂; SEQ ID NO: 54 Ac-Nle-c(Cys-D-Ala-His-D-Phe-Arg-Trp-D-Ala-Cys)-NH₂; SEQ ID NO: 54 Ac-Nle-c(Cys-D-Ala-His-D-Phe-Arg-Trp-β-Ala-Cys)-NH₂; SEQ ID NO: 54 Ac-Nle-c(Cys-D-Ala-His-D-Phe-Arg-Trp-Gaba-Cys)-NH₂; SEQ ID NO: 54 Ac-Nle-c(Cys-D-Ala-His-D-Phe-Arg-Trp-Apn-Cys)-NH₂; SEQ ID NO: 55 Ac-c(Cys-Glu-His-D-Phe-Arg-Trp-Ala-Cys)-NH₂; SEQ ID NO: 55 Ac-c(Cys-Glu-His-D-Phe-Arg-2-Nal-Ala-Cys)-NH₂; SEQ ID NO: 56 Ac-c(Cys-D-Ala-His-D-Phe-Arg-Trp-Ala-Cys)-NH₂; SEQ ID NO: 56 Ac-c(Cys-D-Ala-His-D-Phe-Arg-2-Nal-Ala-Cys)-NH₂; SEQ ID NO: 57 Ac-Nle-c(Cys-D-Ala-His-D-Phe-Arg-Trp-Ala-Cys)-NH₂; SEQ ID NO: 57 Ac-Nle-c(Cys-D-Ala-His-D-Phe-Arg-Trp-β-Ala-Cys)-NH₂; SEQ ID NO: 58 Ac-Nle-c(Asp-D-Ala-His-D-Phe-Arg-Bal-Ala-Lys)-NH₂; (SEQ ID NO: 60) Tyr-Gly-Arg-(Lys)₂-(Arg)₂-Gln-(Arg)₃-Nle-c(Asp-His-D-2-Nal-Arg-Trp-Lys)-NH₂; (SEQ ID NO: 61) Tyr-Gly-Arg-(Lys)₂-(Arg)₂-Gln-(Arg)₃-Doc-Nle-c(Asp-His-D-2-Nal-Arg-Trp-Lys)- NH₂; (SEQ ID NO: 62) Nle-c(Asp-His-D-2-Nal-Arg-Trp-Lys)-β-Ala-Tyr-Gly-Arg-(Lys)₂-(Arg)₂-Gln-(Arg)₃- NH₂; (SEQ ID NO: 62) Ac-Nle-c(Asp-His-D-2-Nal-Arg-Trp-Lys)-β-Ala-Tyr-Gly-Arg-(Lys)₂-(Arg)₂-Gln- (Arg)₃-NH₂; (SEQ ID NO: 63) Nle-c(Asp-His-D-2-Nal-Arg-Trp-Lys)-(Doc)₂-Tyr-Gly-Arg-(Lys)₂-(Arg)₂-Gln-(Arg)₃- NH₂; (SEQ ID NO: 64) Ac-Nle-c(Asp-His-D-2-Nal-Arg-Trp-Lys)-(Pro)₂-Lys-Asp-Tyr-Gly-Arg-(Lys)₂-(Arg)₂- Gln-(Arg)₃-NH₂; (SEQ ID NO: 65) Ac-c(Cys-Glu-His-D-2-Nal-Arg-Trp-Gly-Cys)-(Pro)₂-Lys-Asp-Tyr-Gly-Arg-(Lys)₂- (Arg)₂-Gln-(Arg)₃-NH₂; (SEQ ID NO 66) Ac-Nle-c(Asp-His-D-2-Nal-Arg-Trp-Lys)-(β-Ala)₂-Tyr-Gly-Arg-(Lys)₂-(Arg)₂-Gln- (Arg)₃-NH₂; (SEQ ID NO: 67) Ac-Nle-c(Asp-His-D-2-Nal-Arg-Trp-Lys)-(Pro)₂-Lys-Asp-Doc-Tyr-Gly-Arg-(Lys)₂- (Arg)₂-Gln-(Arg)₃-NH₂; (SEQ ID NO: 68) Ac-c(Cys-Glu-His-D-2-Nal-Arg-Trp-Gly-Cys)-(Pro)₂-Lys-Asp-Doc-Tyr-Gly-Arg- (Lys)₂-(Arg)₂-Gln-(Arg)₃-NH₂; (SEQ ID NO: 69) Ac-c(Cys-Glu-His-D-2-Nal-Arg-Trp-Ala-Cys)-(Pro)₂-Lys-Asp-β-Ala-Tyr-Gly-Arg- (Lys)₂-(Arg)₂-Gln-(Arg)₃-NH₂; (SEQ ID NO: 69) Ac-c(Cys-Glu-His-D-2-Nal-Arg-Trp-Ala-Cys)-(Pro)₂-Lys-Asp-Doc-Tyr-Gly-Arg- (Lys)₂-(Arg)₂-Gln-(Arg)₃-NH₂; (SEQ ID NO: 70) Ac-Nle-c(Asp-His-D-2-Nal-Arg-Trp-Lys)-(Doc)₂-Tyr-Gly-Arg-(Lys)₂-(Arg)₂-Gln- (Arg)₃-NH₂; (SEQ ID NO: 71) Ac-c(Cys-Glu-His-D-2-Nal-Arg-2-Nal-Ala-Cys)-(Pro)₂-Lys-Asp-β-Ala-Tyr-Gly-Arg- (Lys)₂-(Arg)₂-Gln-(Arg)₃-NH₂; (SEQ ID NO: 72) Ac-c(Cys-Glu-His-D-2-Nal-Arg-Bal-Ala-Cys)-(Pro)₂-Lys-Asp-β-Ala-(Arg)₅-Gln- (Arg)₃-NH₂; (SEQ ID NO: 73) Ac-c(Cys-Glu-His-D-2-Nal-Arg-Bal-Ala-Cys)-(Pro)₂-Lys-Asp-β-Ala-Gly-(Arg)₅-Gln- (Arg)₃-NH₂; (SEQ ID NO: 74) Ac-c(Cys-Glu-His-D-2-Nal-Arg-Bal-Ala-Cys)-(Pro)₂-Lys-Asp-β-Ala-Tyr-Gly-(Arg)₅- Gln-(Arg)₃-NH₂; (SEQ ID NO: 75) Ac-c(Cys-Glu-His-D-2-Nal-Arg-Trp-Ala-Cys)-(Pro)₂-Lys-Asp-β-Ala-Tyr-Gly-Arg- (Lys)₂-Arg-Gln-(Arg)₄-NH₂; (SEQ ID NO: 76) Ac-c(Cys-Glu-His-D-2-Nal-Arg-Trp-Ala-Cys)-(Pro)₂-Lys-Asp-β-Ala-Tyr-Gly-Arg- (Lys)₂-Gln-(Arg)₅-NH₂; (SEQ ID NO: 77) Ac-c(Cys-Glu-His-D-2-Nal-Arg-Trp-Ala-Cys)-(Pro)₂-Lys-Asp-β-Ala-Tyr-Gly-Arg- Lys-Gln-Lys-(Arg)₅-NH₂; (SEQ ID NO: 78) Ac-c(Cys-Glu-His-D-2-Nal-Arg-Trp-Ala-Cys)-(Pro)₂-Lys-Asp-β-Ala-Tyr-Gly-Arg- (Lys)₂-(Arg)₄-Gln-Arg-NH₂; (SEQ ID NO: 79) Ac-c(Cys-Glu-His-D-2-Nal-Arg-Bal-Ala-Cys)-(Pro)₂-Lys-Asp-β-Ala-Tyr-Aib-Arg- (Lys)₂-(Arg)₂-Gln-(Arg)₃-NH₂; (SEQ ID NO: 80) Ac-c(Cys-Glu-His-D-2-Nal-Arg-1-Nal-Ala-Cys)-(Pro)₂-Arg-Asp-β-Ala-(Arg)₅-Gln- (Arg)₃-NH₂; (SEQ ID NO: 80) Ac-c(Cys-Glu-His-D-2-Nal-Arg-1-Nal-Ala-Cys)-(Pro)₂-Lys-Asp-β-Ala-(Arg)₅-Gln- (Arg)₃-NH₂; (SEQ ID NO: 81) Ac-c(Cys-Glu-His-D-2-Nal-Arg-1-Nal-Ala-Cys)-(Pro)₂-Lys-Asp-β-Ala-(Arg)₆-Gln- (Arg)₃-NH₂; (SEQ ID NO: 82) Ac-c(Cys-Glu-His-D-2-Nal-Arg-2-Nal-Ala-Cys)-(Pro)₂-Arg-Asp-β-Ala-(Arg)₅-Gln- (Arg)₃-NH₂; (SEQ ID NO: 82) Ac-c(Cys-Glu-His-D-2-Nal-Arg-2-Nal-Ala-Cys)-(Pro)₂-Lys-Asp-β-Ala-(Arg)₅-Gln- (Arg)₃-NH₂; (SEQ ID NO: 81) Ac-c(Cys-Glu-His-D-2-Nal-Arg-2-Nal-Ala-Cys)-(Pro)₂-Lys-Asp-β-Ala-(Arg)₆-Gln- (Arg)₃-NH₂; (SEQ ID NO: 83) Ac-c(Cys-Glu-His-D-2-Nal-Arg-Bal-Ala-Cys)-(Pro)₂-Arg-Asp-β-Ala-(Arg)₆-Gln- (Arg)₃-NH₂; (SEQ ID NO: 84) Ac-c(Cys-Glu-His-D-2-Nal-Arg-Bal-Ala-Cys)-(Pro)₂-Arg-Asp-β-Ala-(Arg)₅-Gln- (Arg)₃-NH₂; (SEQ ID NO: 83) Ac-c(Cys-Glu-His-D-2-Nal-Arg-Bal-Ala-Cys)-(Pro)₂-Lys-Asp-β-Ala-(Arg)₆-Gln- (Arg)₃-NH₂; (SEQ ID NO: 85) Ac-c(Cys-Glu-His-D-2-Nal-Arg-Trp-Ala-Cys)-(Pro)₂-Lys-Asp-β-Ala-Tyr-Gly-Arg- (Lys)₂-(Arg)₃-Gln-(Arg)₂-NH₂; (SEQ ID NO: 86) Ac-c(Cys-Glu-His-D-2-Nal-Arg-Trp-Ala-Cys)-(Pro)₂-Lys-Asp-β-Ala-Tyr-Gly-Arg- Gln-(Lys)₂-(Arg)₅-NH₂; (SEQ ID NO: 87) Ac-c(Cys-Glu-His-D-2-Nal-Arg-Trp-Ala-Cys)-(Pro)₂-Lys-Asp-β-Ala-Tyr-Gly-Arg- (Lys)₂-(Arg)₅-Gln-NH₂; (SEQ ID NO: 71) Ac-c(Cys-Glu-His-D-2-Nal-Arg-1-Nal-Ala-Cys)-(Pro)₂-Lys-Asp-β-Ala-Tyr-Gly-Arg- (Lys)₂-(Arg)₂-Gln-(Arg)₃-NH₂; (SEQ ID NO: 71) Ac-c(Cys-Glu-His-D-2-Nal-Arg-Bal-Ala-Cys)-(Pro)₂-Lys-Asp-β-Ala-Tyr-Gly-Arg- (Lys)₂-(Arg)₂-Gln-(Arg)₃-NH₂; (SEQ ID NO: 88) Ac-c(Cys-Glu-His-D-2-Nal-Arg-1-Nal-Ala-Cys)-(Pro)₂-Lys-Asp-β-Ala-(Arg)₂-Lys- (Arg)₂-Gln-(Arg)₃-NH₂; (SEQ ID NO: 89) Ac-c(Cys-Glu-His-D-2-Nal-Arg-1-Nal-Ala-Cys)-(Pro)₂-Lys-Asp-β-Ala-Arg-Lys- (Arg)₃-Gln-(Arg)₃-NH₂; (SEQ ID NO: 88) Ac-c(Cys-Glu-His-D-2-Nal-Arg-2-Nal-Ala-Cys)-(Pro)₂-Lys-Asp-β-Ala-(Arg)₂-Lys- (Arg)₂-Gln-(Arg)₃-NH₂; (SEQ ID NO: 90) Ac-c(Cys-Glu-His-D-2-Nal-Arg-2-Nal-Ala-Cys)-(Pro)₂-Lys-Asp-β-Ala-Tyr-Gly-(Arg)₂- Lys-(Arg)₂-Gln-(Arg)₃-NH₂; (SEQ ID NO: 91) Ac-c(Cys-Glu-His-D-2-Nal-Arg-2-Nal-Ala-Cys)-(Pro)₂-Lys-Asp-β-Ala-Gly-(Arg)₂-Lys- (Arg)₂-Gln-(Arg)₃-NH₂; (SEQ ID NO: 92) Ac-c(Cys-Glu-His-D-2-Nal-Arg-2-Nal-Ala-Cys)-(Pro)₂-Lys-Asp-β-Ala-Gly-Arg-Lys- (Arg)₃-Gln-(Arg)₃-NH₂; (SEQ ID NO: 95) Ac-c(Cys-Glu-His-D-2-Nal-Arg-1-Nal-Ala-Cys)-(Pro)₂-Lys-Asp-β-Ala-Tyr-Gly-(Arg)₂- Lys-(Arg)₂-Gln-(Arg)₃-NH₂; (SEQ ID NO: 96) Ac-c(Cys-Glu-His-D-2-Nal-Arg-1-Nal-Ala-Cys)-(Pro)₂-Lys-Asp-β-Ala-Tyr-Gly-Arg- Lys-(Arg)₃-Gln-(Arg)₃-NH₂; (SEQ ID NO: 97) Ac-c(Cys-Glu-His-D-2-Nal-Arg-1-Nal-Ala-Cys)-(Pro)₂-Lys-Asp-β-Ala-Gly-(Arg)₂-Lys- (Arg)₂-Gln-(Arg)₃-NH₂; (SEQ ID NO: 92) Ac-c(Cys-Glu-His-D-2-Nal-Arg-1-Nal-Ala-Cys)-(Pro)₂-Lys-Asp-β-Ala-Gly-Arg-Lys- (Arg)₃-Gln-(Arg)₃-NH₂; (SEQ ID NO: 98) Ac-c(Cys-Glu-His-D-2-Nal-Arg-2-Nal-Ala-Cys)-(Pro)₂-Lys-Asp-β-Ala-(Arg)₂-Lys- (Arg)₂-Gln-(Arg)₃-NH₂; (SEQ ID NO: 99) Ac-c(Cys-Glu-His-D-2-Nal-Arg-2-Nal-Ala-Cys)-(Pro)₂-Lys-Asp-β-Ala-Arg-Lys- (Arg)₃-Gln-(Arg)₃-NH₂; (SEQ ID NO: 101) Ac-c(Cys-Glu-His-D-2-Nal-Arg-2-Nal-Ala-Cys)-(Pro)₂-Lys-Asp-β-Ala-Tyr-Gly-Arg- Lys-(Arg)₃-Gln-(Arg)₃-NH₂; (SEQ ID NO: 104) Ac-c(Cys-Glu-His-D-2-Nal-Arg-Bal-Ala-Cys)-(Pro)₂-Lys-Asp-β-Ala-(Arg)₂-Lys- (Arg)₂-Gln-(Arg)₃-NH₂; (SEQ ID NO: 105) Ac-c(Cys-Glu-His-D-2-Nal-Arg-Bal-Ala-Cys)-(Pro)₂-Lys-Asp-β-Ala-Arg-Lys-(Arg)₃- Gln-(Arg)₃-NH₂; (SEQ ID NO: 100) Ac-c(Cys-Glu-His-D-2-Nal-Arg-Bal-Ala-Cys)-(Pro)₂-Lys-Asp-β-Ala-Tyr-Gly-(Arg)₂- Lys-(Arg)₂-Gln-(Arg)₃-NH₂; (SEQ ID NO: 101) Ac-c(Cys-Glu-His-D-2-Nal-Arg-Bal-Ala-Cys)-(Pro)₂-Lys-Asp-β-Ala-Tyr-Gly-Arg-Lys- (Arg)₃-Gln-(Arg)₃-NH₂; (SEQ ID NO: 102) Ac-c(Cys-Glu-His-D-2-Nal-Arg-Bal-Ala-Cys)-(Pro)₂-Lys-Asp-β-Ala-Gly-(Arg)₂-Lys- (Arg)₂-Gln-(Arg)₃-NH₂; (SEQ ID NO: 103) Ac-c(Cys-Glu-His-D-2-Nal-Arg-Bal-Ala-Cys)-(Pro)₂-Lys-Asp-β-Ala-Gly-Arg-Lys- (Arg)₃-Gln-(Arg)₃-NH₂; (SEQ ID NO: 113) Ac-c(Cys-Glu-His-D-2-Nal-Arg-Trp-Ala-Cys)-(Pro)₂-Lys-Asp-β-Ala-(Arg)₅-Gln- (Arg)₃-NH₂; (SEQ ID NO: 113) Ac-c(Cys-Glu-His-D-2-Nal-Arg-Trp-Ala-Cys)-(Pro)₂-Arg-Asp-β-Ala-(Arg)₅-Gln- (Arg)₃-NH₂; (SEQ ID NO: 114) Ac-c(Cys-Glu-His-D-2-Nal-Arg-Trp-Ala-Cys)-(Pro)₂-Lys-Asp-β-Ala-Tyr-Gly-(Arg)₅- Gln-(Arg)₃-NH₂; (SEQ ID NO: 114) Ac-c(Cys-Glu-His-D-2-Nal-Arg-Trp-Ala-Cys)-(Pro)₂-Arg-Asp-β-Ala-Tyr-Gly-(Arg)₅- Gln-(Arg)₃-NH₂; (SEQ ID NO: 115) Ac-c(Cys-Glu-His-D-2-Nal-Arg-Trp-Ala-Cys)-(Pro)₂-Lys-Asp-β-Ala-(Arg)₅-Gln- (Arg)₄-NH₂; (SEQ ID NO: 115) Ac-c(Cys-Glu-His-D-2-Nal-Arg-Trp-Ala-Cys)-(Pro)₂-Arg-Asp-β-Ala-(Arg)₅-Gln- (Arg)₄-NH₂; (SEQ ID NO: 116) Ac-c(Cys-Glu-His-D-2-Nal-Arg-Trp-Ala-Cys)-(Pro)₂-Lys-Asp-β-Ala-Tyr-Gly-(Arg)₅- Gln-(Arg)₄-NH₂; (SEQ ID NO: 116) Ac-c(Cys-Glu-His-D-2-Nal-Arg-Trp-Ala-Cys)-(Pro)₂-Arg-Asp-β-Ala-Tyr-Gly-(Arg)₅- Gln-(Arg)₄-NH₂; (SEQ ID NO: 118) Ac-c(Cys-Glu-His-D-2-Nal-Arg-1-Nal-Ala-Cys)-(Pro)₂-Lys-Asp-β-Ala-(Arg)₅-Gln- (Arg)₄-NH₂; (SEQ ID NO: 118) Ac-c(Cys-Glu-His-D-2-Nal-Arg-1-Nal-Ala-Cys)-(Pro)₂-Arg-Asp-β-Ala-(Arg)₅-Gln- (Arg)₄-NH₂; (SEQ ID NO: 119) Ac-c(Cys-Glu-His-D-2-Nal-Arg-1-Nal-Ala-Cys)-(Pro)₂-Arg-Asp-β-Ala-(Arg)₆-Gln- (Arg)₃-NH₂; (SEQ ID NO: 120) Ac-c(Cys-Glu-His-D-2-Nal-Arg-1-Nal-Ala-Cys)-(Pro)₂-Lys-Asp-β-Ala-Tyr-Gly-(Arg)₅- Gln-(Arg)₃-NH₂; (SEQ ID NO: 120) Ac-c(Cys-Glu-His-D-2-Nal-Arg-1-Nal-Ala-Cys)-(Pro)₂-Arg-Asp-β-Ala-Tyr-Gly- (Arg)₅-Gln-(Arg)₃-NH₂; (SEQ ID NO: 121) Ac-c(Cys-Glu-His-D-2-Nal-Arg-1-Nal-Ala-Cys)-(Pro)₂-Lys-Asp-β-Ala-Tyr-Gly-(Arg)₅- Gln-(Arg)₄-NH₂; (SEQ ID NO: 121) Ac-c(Cys-Glu-His-D-2-Nal-Arg-1-Nal-Ala-Cys)-(Pro)₂-Arg-Asp-β-Ala-Tyr-Gly- (Arg)₅-Gln-(Arg)₄-NH₂; (SEQ ID NO: 122) Ac-c(Cys-Glu-His-D-2-Nal-Arg-1-Nal-Ala-Cys)-(Pro)₂-Lys-Asp-β-Ala-Tyr-Gly-(Arg)₆- Gln-(Arg)₃-NH₂; (SEQ ID NO: 122) Ac-c(Cys-Glu-His-D-2-Nal-Arg-1-Nal-Ala-Cys)-(Pro)₂-Arg-Asp-β-Ala-Tyr-Gly- (Arg)₆-Gln-(Arg)₃-NH₂; (SEQ ID NO: 124) Ac-c(Cys-Glu-His-D-2-Nal-Arg-2-Nal-Ala-Cys)-(Pro)₂-Arg-Asp-β-Ala-(Arg)₆-Gln- (Arg)₃-NH₂; (SEQ ID NO: 125) Ac-c(Cys-Glu-His-D-2-Nal-Arg-2-Nal-Ala-Cys)-(Pro)₂-Lys-Asp-β-Ala-(Arg)₅-Gln- (Arg)₄-NH₂; (SEQ ID NO: 125) Ac-c(Cys-Glu-His-D-2-Nal-Arg-2-Nal-Ala-Cys)-(Pro)₂-Arg-Asp-β-Ala-(Arg)₅-Gln- (Arg)₄-NH₂; (SEQ ID NO: 126) Ac-c(Cys-Glu-His-D-2-Nal-Arg-2-Nal-Ala-Cys)-(Pro)₂-Lys-Asp-β-Ala-Tyr-Gly-(Arg)₅- Gln-(Arg)₃-NH₂; (SEQ ID NO: 126) Ac-c(Cys-Glu-His-D-2-Nal-Arg-2-Nal-Ala-Cys)-(Pro)₂-Arg-Asp-β-Ala-Tyr-Gly- (Arg)₅-Gln-(Arg)₃-NH₂; (SEQ ID NO: 127) Ac-c(Cys-Glu-His-D-2-Nal-Arg-2-Nal-Ala-Cys)-(Pro)₂-Lys-Asp-β-Ala-Tyr-Gly-(Arg)₆- Gln-(Arg)₃-NH₂; (SEQ ID NO: 127) Ac-c(Cys-Glu-His-D-2-Nal-Arg-2-Nal-Ala-Cys)-(Pro)₂-Arg-Asp-β-Ala-Tyr-Gly- (Arg)₆-Gln-(Arg)₃-NH₂; (SEQ ID NO: 128) Ac-c(Cys-Glu-His-D-2-Nal-Arg-2-Nal-Ala-Cys)-(Pro)₂-Lys-Asp-β-Ala-Tyr-Gly-(Arg)₅- Gln-(Arg)₄-NH₂; (SEQ ID NO: 128) Ac-c(Cys-Glu-His-D-2-Nal-Arg-2-Nal-Ala-Cys)-(Pro)₂-Arg-Asp-β-Ala-Tyr-Gly- (Arg)₅-Gln-(Arg)₄-NH₂; (SEQ ID NO: 130) Ac-c(Cys-Glu-His-D-2-Nal-Arg-Bal-Ala-Cys)-(Pro)₂-Lys-Asp-β-Ala-(Arg)₅-Gln- (Arg)₄-NH₂; (SEQ ID NO: 130) Ac-c(Cys-Glu-His-D-2-Nal-Arg-Bal-Ala-Cys)-(Pro)₂-Arg-Asp-β-Ala-(Arg)₅-Gln- (Arg)₄-NH₂; (SEQ ID NO: 133) Ac-c(Cys-Glu-His-D-2-Nal-Arg-Bal-Ala-Cys)-(Pro)₂-Arg-Asp-β-Ala-Tyr-Gly-(Arg)₅- Gln-(Arg)₃-NH₂; (SEQ ID NO: 134) Ac-c(Cys-Glu-His-D-2-Nal-Arg-Bal-Ala-Cys)-(Pro)₂-Lys-Asp-β-Ala-Tyr-Gly-(Arg)₅- Gln-(Arg)₄-NH₂; (SEQ ID NO: 134) Ac-c(Cys-Glu-His-D-2-Nal-Arg-Bal-Ala-Cys)-(Pro)₂-Arg-Asp-β-Ala-Tyr-Gly-(Arg)₅- Gln-(Arg)₄-NH₂; (SEQ ID NO: 135) Ac-c(Cys-Glu-His-D-2-Nal-Arg-Bal-Ala-Cys)-(Pro)₂-Lys-Asp-β-Ala-Tyr-Gly-(Arg)₆- Gln-(Arg)₃-NH₂; (SEQ ID NO: 135) Ac-c(Cys-Glu-His-D-2-Nal-Arg-Bal-Ala-Cys)-(Pro)₂-Arg-Asp-β-Ala-Tyr-Gly-(Arg)₆- Gln-(Arg)₃-NH₂; (SEQ ID NO: 136) Ac-Nle-c(Cys-D-Ala-His-D-Phe-Arg-Trp-Cys)-(Doc)₂-Tyr-Gly-Arg-(Lys)₂-(Arg)₂-Gln- (Arg)₃-NH₂; (SEQ ID NO: 137) Ac-Nle-c(Cys-D-Ala-His-D-Phe-Arg-Trp-Cys)-β-Ala-Tyr-Gly-Arg-(Lys)₂-Arg-Gln- (Arg)₄-NH₂; (SEQ ID NO: 136) Ac-Nle-c(Cys-D-Ala-His-D-Phe-Arg-Trp-Cys)-Doc-Tyr-Gly-Arg-(Lys)₂-(Arg)₂-Gln- (Arg)₃-NH₂; (SEQ ID NO: 138) Ac-Nle-c(Cys-D-Ala-His-D-Phe-Arg-Trp-Cys)-β-Ala-(Arg)₅-Gln-(Arg)₃-NH₂; (SEQ ID NO: 138) Ac-Nle-c(Cys-D-Ala-His-D-Phe-Arg-Trp-Cys)-β-Ala-Gly-(Arg)₅-Gln-(Arg)₃-NH₂; (SEQ ID NO: 139) Ac-Nle-c(Cys-D-Ala-His-D-Phe-Arg-Trp-Cys)-β-Ala-Tyr-Gly-(Arg)₅-Gln-(Arg)₃-NH₂; (SEQ ID NO: 140) Ac-Nle-c(Cys-D-Ala-His-D-Phe-Arg-Trp-Cys)-β-Ala-Gly-(Arg)₅-Gln-(Arg)₄-NH₂; (SEQ ID NO: 141) Ac-Nle-c(Cys-D-Ala-His-D-Phe-Arg-Trp-Cys)-β-Ala-Tyr-Gly-(Arg)₂-Lys-(Arg)₂-Gln- (Arg)₃-NH₂; (SEQ ID NO: 142) Ac-Nle-c(Cys-D-Ala-His-D-Phe-Arg-Trp-Cys)-β-Ala-Tyr-Gly-Arg-Lys-(Arg)₃-Gln- (Arg)₃-NH₂; (SEQ ID NO: 141) Ac-Nle-c(Cys-D-Ala-His-D-Phe-Arg-Trp-Cys)-β-Ala-Gly-(Arg)₂-Lys-(Arg)₂-Gln- (Arg)₃-NH₂; (SEQ ID NO: 142) Ac-Nle-c(Cys-D-Ala-His-D-Phe-Arg-Trp-Cys)-β-Ala-Gly-Arg-Lys-(Arg)₃-Gln-(Arg)₃- NH₂; (SEQ ID NO: 143) Ac-Nle-c(Cys-D-Ala-His-D-Phe-Arg-Trp-Cys)-β-Ala-(Arg)₂-Lys-(Arg)₂-Gln-(Arg)₃- NH₂; (SEQ ID NO: 144) Ac-Nle-c(Cys-D-Ala-His-D-Phe-Arg-Trp-Cys)-β-Ala-Arg-Lys-(Arg)₃-Gln-(Arg)₃-NH₂; (SEQ ID NO: 148) Ac-Nle-c(Cys-D-Ala-His-D-Phe-Arg-Trp-Cys)-β-Ala-(Arg)₅-Gln-(Arg)₃-NH₂; (SEQ ID NO: 148) Ac-Nle-c(Cys-D-Ala-His-D-Phe-Arg-Trp-Cys)-(β-Ala)₂-(Arg)₅-Gln-(Arg)₃-NH₂; (SEQ ID NO: 149) Ac-Nle-c(Cys-D-Ala-His-D-Phe-Arg-Trp-Cys)-(β-Ala)₂-Gly-(Arg)₅-Gln-(Arg)₃-NH_(2;); (SEQ ID NO: 149) Ac-Nle-c(Cys-D-Ala-His-D-Phe-Arg-Trp-Cys)-(β-Ala)₂-Tyr-Gly-(Arg)₅-Gln-(Arg)₃- NH₂; (SEQ ID NO: 151) Ac-Nle-c(Cys-D-Ala-His-D-Phe-Arg-Trp-Cys)-Doc-(Arg)₅-Gln-(Arg)₃-NH₂; (SEQ ID NO: 150) Ac-Nle-c(Cys-D-Ala-His-D-Phe-Arg-Trp-Cys)-Doc-Gly-(Arg)₅-Gln-(Arg)₃-NH₂; (SEQ ID NO: 150) Ac-Nle-c(Cys-D-Ala-His-D-Phe-Arg-Trp-Cys)-Doc-Tyr-Gly-(Arg)₅-Gln-(Arg)₃-NH₂; (SEQ ID NO: 151) Ac-Nle-c(Cys-D-Ala-His-D-Phe-Arg-Trp-Cys)-(Doc)₂-(Arg)₅-Gln-(Arg)₃-NH₂; (SEQ ID NO: 152) Ac-Nle-c(Cys-D-Ala-His-D-Phe-Arg-Trp-Cys)-(Doc)₂-Gly-(Arg)₅-Gln-(Arg)₃-NH₂; (SEQ ID NO: 152) Ac-Nle-c(Cys-D-Ala-His-D-Phe-Arg-Trp-Cys)-(Doc)₂-Tyr-Gly-(Arg)₅-Gln-(Arg)₃-NH₂; (SEQ ID NO: 154) Ac-Nle-c(Cys-D-Ala-His-D-Phe-Arg-Trp-Cys)-β-Ala-(Arg)₅-Gln-(Arg)₄-NH₂; (SEQ ID NO: 153) Ac-Nle-c(Cys-D-Ala-His-D-Phe-Arg-Trp-Cys)-β-Ala-Tyr-Gly-(Arg)₅-Gln-(Arg)₄-NH₂; (SEQ ID NO: 154) Ac-Nle-c(Cys-D-Ala-His-D-Phe-Arg-Trp-Cys)-(β-Ala)₂-(Arg)₅-Gln-(Arg)₄-NH₂; (SEQ ID NO: 155) Ac-Nle-c(Cys-D-Ala-His-D-Phe-Arg-Trp-Cys)-(β-Ala)₂-Gly-(Arg)₅-Gln-(Arg)₄-NH₂; (SEQ ID NO: 155) Ac-Nle-c(Cys-D-Ala-His-D-Phe-Arg-Trp-Cys)-(β-Ala)₂-Tyr-Gly-(Arg)₅-Gln-(Arg)₄- NH₂; (SEQ ID NO: 157) Ac-Nle-c(Cys-D-Ala-His-D-Phe-Arg-Trp-Cys)-Doc-(Arg)₅-Gln-(Arg)₄-NH₂; (SEQ ID NO: 156) Ac-Nle-c(Cys-D-Ala-His-D-Phe-Arg-Trp-Cys)-Doc-Gly-(Arg)₅-Gln-(Arg)₄-NH₂; (SEQ ID NO: 156) Ac-Nle-c(Cys-D-Ala-His-D-Phe-Arg-Trp-Cys)-Doc-Tyr-Gly-(Arg)₅-Gln-(Arg)₄-NH₂; (SEQ ID NO: 157) Ac-Nle-c(Cys-D-Ala-His-D-Phe-Arg-Trp-Cys)-(Doc)₂-(Arg)₅-Gln-(Arg)₄-NH₂; (SEQ ID NO: 158) Ac-Nle-c(Cys-D-Ala-His-D-Phe-Arg-Trp-Cys)-(Doc)₂-Gly-(Arg)₅-Gln-(Arg)₄-NH₂; (SEQ ID NO: 158) Ac-Nle-c(Cys-D-Ala-His-D-Phe-Arg-Trp-Cys)-(Doc)₂-Tyr-Gly-(Arg)₅-Gln-(Arg)₄-NH₂; (SEQ ID NO: 159) Ac-Nle-c(Cys-His-D-Phe-Arg-Trp-Gaba-Cys)-β-Ala-Tyr-Gly-(Arg)₅-Gln-(Arg)₃-NH₂; (SEQ ID NO: 160) Ac-Nle-c(Cys-His-D-Phe-Arg-Trp-Gaba-Cys)-β-Ala-(Arg)₅-Gln-(Arg)₃-NH₂; (SEQ ID NO: 161) Ac-Nle-c(Asp-His-D-Phe-Arg-Trp-Ala-Lys)-β-Ala-Tyr-Gly-(Arg)₅-Gln-(Arg)₃-NH₂; (SEQ ID NO: 162) Ac-Nle-c(Asp-His-D-Phe-Arg-Trp-Ala-Lys)-β-Ala-(Arg)₅-Gln-(Arg)₃-NH₂; (SEQ ID NO: 164) Ac-Nle-c(Asp-His-D-Phe-Arg-Trp-Lys)-β-Ala-Tyr-Gly-(Arg)₅-Gln-(Arg)₃-NH₂; (SEQ ID NO: 163) Ac-Nle-c(Asp-His-D-Phe-Arg-Trp-Lys)-β-Ala-Gly-(Arg)₅-Gln-(Arg)₃-NH₂; (SEQ ID NO: 163) Ac-Nle-c(Asp-His-D-Phe-Arg-Trp-Lys)-β-Ala-(Arg)₅-Gln-(Arg)₃-NH₂; (SEQ ID NO: 164) Ac-Nle-c(Asp-His-D-Phe-Arg-Trp-Lys)-(β-Ala)₂-Tyr-Gly-(Arg)₅-Gln-(Arg)₃-NH₂; (SEQ ID NO: 165) Ac-Nle-c(Asp-His-D-Phe-Arg-Trp-Lys)-(β-Ala)₂-Gly-(Arg)₅-Gln-(Arg)₃-NH₂; (SEQ ID NO: 165) Ac-Nle-c(Asp-His-D-Phe-Arg-Trp-Lys)-(β-Ala)₂-(Arg)₅-Gln-(Arg)₃-NH₂; (SEQ ID NO: 166) Ac-Nle-c(Asp-His-D-Phe-Arg-Trp-Lys)-Doc-Tyr-Gly-(Arg)₅-Gln-(Arg)₃-NH₂; (SEQ ID NO: 166) Ac-Nle-c(Asp-His-D-Phe-Arg-Trp-Lys)-Doc-Gly-(Arg)₅-Gln-(Arg)₃-NH₂; (SEQ ID NO: 168) Ac-Nle-c(Asp-His-D-Phe-Arg-Trp-Lys)-Doc-(Arg)₅-Gln-(Arg)₃-NH₂; (SEQ ID NO: 167) Ac-Nle-c(Asp-His-D-Phe-Arg-Trp-Lys)-(Doc)₂-Tyr-Gly-(Arg)₅-Gln-(Arg)₃-NH₂; (SEQ ID NO: 167) Ac-Nle-c(Asp-His-D-Phe-Arg-Trp-Lys)-(Doc)₂-Gly-(Arg)₅-Gln-(Arg)₃-NH₂; (SEQ ID NO: 168) Ac-Nle-c(Asp-His-D-Phe-Arg-Trp-Lys)-(Doc)₂-(Arg)₅-Gln-(Arg)₃-NH₂; (SEQ ID NO: 170) Ac-Nle-c(Asp-His-D-Phe-Arg-Trp-Lys)-β-Ala-Tyr-Gly-(Arg)₅-Gln-(Arg)₄-NH₂; (SEQ ID NO: 169) Ac-Nle-c(Asp-His-D-Phe-Arg-Trp-Lys)-β-Ala-Gly-(Arg)₅-Gln-(Arg)₄-NH₂; (SEQ ID NO: 169) Ac-Nle-c(Asp-His-D-Phe-Arg-Trp-Lys)-β-Ala-(Arg)₅-Gln-(Arg)₄-NH₂; (SEQ ID NO: 170) Ac-Nle-c(Asp-His-D-Phe-Arg-Trp-Lys)-(β-Ala)₂-Tyr-Gly-(Arg)₅-Gln-(Arg)₄-NH₂; (SEQ ID NO: 171) Ac-Nle-c(Asp-His-D-Phe-Arg-Trp-Lys)-(β-Ala)₂-Gly-(Arg)₅-Gln-(Arg)₄-NH₂; (SEQ ID NO: 171) Ac-Nle-c(Asp-His-D-Phe-Arg-Trp-Lys)-(β-Ala)₂-(Arg)₅-Gln-(Arg)₄-NH₂; (SEQ ID NO: 173) Ac-Nle-c(Asp-His-D-Phe-Arg-Trp-Lys)-Doc-Tyr-Gly-(Arg)₅-Gln-(Arg)₄-NH₂; (SEQ ID NO: 172) Ac-Nle-c(Asp-His-D-Phe-Arg-Trp-Lys)-Doc-Gly-(Arg)₅-Gln-(Arg)₄-NH₂; (SEQ ID NO: 172) Ac-Nle-c(Asp-His-D-Phe-Arg-Trp-Lys)-Doc-(Arg)₅-Gln-(Arg)₄-NH₂; (SEQ ID NO: 173) Ac-Nle-c(Asp-His-D-Phe-Arg-Trp-Lys)-(Doc)₂-Tyr-Gly-(Arg)₅-Gln-(Arg)₄-NH₂; (SEQ ID NO: 174) Ac-Nle-c(Asp-His-D-Phe-Arg-Trp-Lys)-(Doc)₂-Gly-(Arg)₅-Gln-(Arg)₄-NH₂; (SEQ ID NO: 174) Ac-Nle-c(Asp-His-D-Phe-Arg-Trp-Lys)-(Doc)₂-(Arg)₅-Gln-(Arg)₄-NH₂; (SEQ ID NO: 175) Ac-Nle-c(Asp-His-D-Phe-Arg-Trp-β-Ala-Lys)-β-Ala-Tyr-Gly-(Arg)₅-Gln-(Arg)₃-NH₂; (SEQ ID NO: 176) Ac-Nle-c(Asp-His-D-Phe-Arg-Trp-β-Ala-Lys)-β-Ala-(Arg)₅-Gln-(Arg)₃-NH₂; (SEQ ID NO: 177) Ac-Nle-c(Cys-His-D-Phe-Arg-Trp-Ahx-Cys)-β-Ala-Tyr-Gly-(Arg)₅-Gln-(Arg)₃-NH₂; (SEQ ID NO: 178) Ac-Nle-c(Cys-His-D-Phe-Arg-Trp-Ahx-Cys)-β-Ala-(Arg)₅-Gln-(Arg)₃-NH₂; (SEQ ID NO: 179) D-Phe-c(Cys-His-D-Phe-Arg-Trp-β-Ala-D-Cys)-Thr-β-Ala-Tyr-Gly-(Arg)₅-Gln-(Arg)₃- NH₂; (SEQ ID NO: 180) D-Phe-c(Cys-His-D-Phe-Arg-Trp-β-Ala-D-Cys)-Thr-β-Ala-(Arg)₅-Gln-(Arg)₃-NH₂; (SEQ ID NO: 181) Ac-Nle-c(Cys-His-D-Phe-Arg-Trp-Apn-Cys)-β-Ala-Tyr-Gly-(Arg)₅-Gln-(Arg)₃-NH₂; (SEQ ID NO: 182) Ac-Nle-c(Cys-His-D-Phe-Arg-Trp-Apn-Cys)-β-Ala-(Arg)₅-Gln-(Arg)₃-NH₂; (SEQ ID NO: 183) Ac-Cha-c(Asp-His-D-Phe-Arg-Trp-Gaba-Lys)-β-Ala-Tyr-Gly-(Arg)₅-Gln-(Arg)₃-NH₂; (SEQ ID NO: 184) Ac-Cha-c(Asp-His-D-Phe-Arg-Trp-Gaba-Lys)-β-Ala-(Arg)₅-Gln-(Arg)₃-NH₂; (SEQ ID NO: 183) Ac-Nle-c(Asp-His-D-Phe-Arg-Trp-Gaba-Lys)-β-Ala-Tyr-Gly-(Arg)₅-Gln-(Arg)₃-NH₂; (SEQ ID NO: 185) Ac-Nle-c(Asp-His-D-Phe-Arg-Trp-Gaba-Lys)-β-Ala-(Arg)₅-Gln-(Arg)₃-NH₂; (SEQ ID NO: 186) Ac-Chg-c(Asp-His-D-Phe-Arg-Trp-Gaba-Lys)-β-Ala-Tyr-Gly-(Arg)₅-Gln-(Arg)₃-NH₂; (SEQ ID NO: 185) Ac-Chg-c(Asp-His-D-Phe-Arg-Trp-Gaba-Lys)-β-Ala-(Arg)₅-Gln-(Arg)₃-NH₂; (SEQ ID NO: 186) Ac-hCha-c(Asp-His-D-Phe-Arg-Trp-Gaba-Lys)-β-Ala-Tyr-Gly-(Arg)₅-Gln-(Arg)₃- NH₂; (SEQ ID NO: 188) Ac-hCha-c(Asp-His-D-Phe-Arg-Trp-Gaba-Lys)-β-Ala-(Arg)₅-Gln-(Arg)₃-NH₂; (SEQ ID NO: 187) Ac-hCha-c(Asp-His-D-Phe-Arg-Trp-Gaba-Lys)-(β-Ala)₂-Tyr-Gly-(Arg)₅-Gln-(Arg)₃- NH₂; (SEQ ID NO: 188) Ac-hCha-c(Asp-His-D-Phe-Arg-Trp-Gaba-Lys)-(β-Ala)₂-(Arg)₅-Gln-(Arg)₃-NH₂; (SEQ ID NO: 189) Ac-hCha-c(Asp-His-D-Phe-Arg-Trp-Gaba-Lys)-Doc-Tyr-Gly-(Arg)₅-Gln-(Arg)₃-NH₂; (SEQ ID NO: 190) Ac-hCha-c(Asp-His-D-Phe-Arg-Trp-Gaba-Lys)-Doc-(Arg)₅-Gln-(Arg)₃-NH₂; (SEQ ID NO: 189) Ac-hCha-c(Asp-His-D-Phe-Arg-Trp-Gaba-Lys)-(Doc)₂-Tyr-Gly-(Arg)₅-Gln-(Arg)₃- NH₂; (SEQ ID NO: 190) Ac-hCha-c(Asp-His-D-Phe-Arg-Trp-Gaba-Lys)-(Doc)₂-(Arg)₅-Gln-(Arg)₃-NH₂; (SEQ ID NO: 191) Ac-hCha-c(Asp-His-D-Phe-Arg-Trp-Gaba-Lys)-β-Ala-Tyr-Gly-(Arg)₅-Gln-(Arg)₄- NH₂; (SEQ ID NO: 192) Ac-hCha-c(Asp-His-D-Phe-Arg-Trp-Gaba-Lys)-β-Ala-(Arg)₅-Gln-(Arg)₄-NH₂; (SEQ ID NO: 191) Ac-hCha-c(Asp-His-D-Phe-Arg-Trp-Gaba-Lys)-(β-Ala)₂-Tyr-Gly-(Arg)₅-Gln-(Arg)₄- NH₂; (SEQ ID NO: 192) Ac-hCha-c(Asp-His-D-Phe-Arg-Trp-Gaba-Lys)-(β-Ala)₂-(Arg)₅-Gln-(Arg)₄-NH₂; (SEQ ID NO: 193) Ac-hCha-c(Asp-His-D-Phe-Arg-Trp-Gaba-Lys)-Doc-Tyr-Gly-(Arg)₅-Gln-(Arg)₄-NH₂; (SEQ ID NO: 194) Ac-hCha-c(Asp-His-D-Phe-Arg-Trp-Gaba-Lys)-Doc-(Arg)₅-Gln-(Arg)₄-NH₂; (SEQ ID NO: 193) Ac-hCha-c(Asp-His-D-Phe-Arg-Trp-Gaba-Lys)-(Doc)₂-Tyr-Gly-(Arg)₅-Gln-(Arg)₄- NH₂; (SEQ ID NO: 194) Ac-hCha-c(Asp-His-D-Phe-Arg-Trp-Gaba-Lys)-(Doc)₂-(Arg)₅-Gln-(Arg)₄-NH₂; (SEQ ID NO: 195) Ac-D-Chg-c(Asp-His-D-Phe-Arg-Trp-Gaba-Lys)-β-Ala-Tyr-Gly-(Arg)₅-Gln-(Arg)₃- NH₂; (SEQ ID NO: 196) Ac-D-Chg-c(Asp-His-D-Phe-Arg-Trp-Gaba-Lys)-β-Ala-(Arg)₅-Gln-(Arg)₃-NH₂; (SEQ ID NO: 197) Ac-hPhe-c(Asp-His-D-Phe-Arg-Trp-Gaba-Lys)-β-Ala-Tyr-Gly-(Arg)₅-Gln-(Arg)₃-NH₂; (SEQ ID NO: 198) Ac-hPhe-c(Asp-His-D-Phe-Arg-Trp-Gaba-Lys)-β-Ala-(Arg)₅-Gln-(Arg)₃-NH₂; (SEQ ID NO: 199) Ac-Nle-c(Cys-His-D-Phe-Arg-D-Trp-Apn-Cys)-β-Ala-Tyr-Gly-(Arg)₅-Gln-(Arg)₃- NH₂; (SEQ ID NO: 200) Ac-Nle-c(Cys-His-D-Phe-Arg-D-Trp-Apn-Cys)-β-Ala-(Arg)₅-Gln-(Arg)₃-NH₂; (SEQ ID NO: 199) Ac-Nle-c(Cys-His-D-Phe-Arg-D-Trp-Ahx-Cys)-β-Ala-Tyr-Gly-(Arg)₅-Gln-(Arg)₃-NH₂; (SEQ ID NO: 200) Ac-Nle-c(Cys-His-D-Phe-Arg-D-Trp-Ahx-Cys)-β-Ala-(Arg)₅-Gln-(Arg)₃-NH₂; (SEQ ID NO: 201) Ac-Nle-c(Cys-His-D-Phe-Arg-D-Trp-β-Ala-Cys)-β-Ala-Tyr-Gly-(Arg)₅-Gln-(Arg)₃- NH₂; (SEQ ID NO: 202) Ac-Nle-c(Cys-His-D-Phe-Arg-D-Trp-β-Ala-Cys)-β-Ala-(Arg)₅-Gln-(Arg)₃-NH₂; (SEQ ID NO: 203) Ac-Nle-c(Cys-D-Ala-His-D-Phe-Arg-Trp-Pen)-β-Ala-Tyr-Gly-(Arg)₅-Gln-(Arg)₃-NH₂; (SEQ ID NO: 203) Ac-Nle-c(Cys-D-Ala-His-D-Phe-Arg-Trp-Pen)-β-Ala-Gly-(Arg)₅-Gln-(Arg)₃-NH₂; (SEQ ID NO: 205) Ac-Nle-c(Cys-D-Ala-His-D-Phe-Arg-Trp-Pen)-β-Ala-(Arg)₅-Gln-(Arg)₃-NH₂; (SEQ ID NO: 204) Ac-Nle-c(Cys-D-Ala-His-D-Phe-Arg-Trp-Pen)-(β-Ala)₂-Tyr-Gly-(Arg)₅-Gln-(Arg)₃- NH₂; (SEQ ID NO: 204) Ac-Nle-c(Cys-D-Ala-His-D-Phe-Arg-Trp-Pen)-(β-Ala)₂-Gly-(Arg)₅-Gln-(Arg)₃-NH₂; (SEQ ID NO: 205) Ac-Nle-c(Cys-D-Ala-His-D-Phe-Arg-Trp-Pen)-(β-Ala)₂-(Arg)₅-Gln-(Arg)₃-NH₂; (SEQ ID NO: 207) Ac-Nle-c(Cys-D-Ala-His-D-Phe-Arg-Trp-Pen)-Doc-Tyr-Gly-(Arg)₅-Gln-(Arg)₃-NH₂; (SEQ ID NO: 206) Ac-Nle-c(Cys-D-Ala-His-D-Phe-Arg-Trp-Pen)-Doc-Gly-(Arg)₅-Gln-(Arg)₃-NH₂; (SEQ ID NO: 206) Ac-Nle-c(Cys-D-Ala-His-D-Phe-Arg-Trp-Pen)-Doc-(Arg)₅-Gln-(Arg)₃-NH₂; (SEQ ID NO: 207) Ac-Nle-c(Cys-D-Ala-His-D-Phe-Arg-Trp-Pen)-(Doc)₂-Tyr-Gly-(Arg)₅-Gln-(Arg)₃-NH₂; (SEQ ID NO: 208) Ac-Nle-c(Cys-D-Ala-His-D-Phe-Arg-Trp-Pen)-(Doc)₂-Gly-(Arg)₅-Gln-(Arg)₃-NH₂; (SEQ ID NO: 208) Ac-Nle-c(Cys-D-Ala-His-D-Phe-Arg-Trp-Pen)-(Doc)₂-(Arg)₅-Gln-(Arg)₃-NH₂; (SEQ ID NO: 209) D-Phe-c(Cys-His-D-(Et)Tyr-Arg-Trp-β-Ala-D-Cys)-β-Ala-Tyr-Gly-(Arg)₅-Gln-(Arg)₃- NH₂; (SEQ ID NO: 210) D-Phe-c(Cys-His-D-(Et)Tyr-Arg-Trp-β-Ala-D-Cys)-β-Ala-(Arg)₅-Gln-(Arg)₃-NH₂; (SEQ ID NO: 209) D-Phe-c(Cys-His-D-(Et)Tyr-Arg-Trp-β-Ala-D-Cys)-β-Ala-Gly-(Arg)₅-Gln-(Arg)₃-NH₂; (SEQ ID NO: 211) D-Phe-c(Cys-His-D-(Et)Tyr-Arg-Trp-β-Ala-D-Cys)-β-Ala-(Arg)₅-Gln-(Arg)₄-NH₂; (SEQ ID NO: 212) D-Phe-c(Cys-His-D-(Et)Tyr-Arg-Trp-β-Ala-D-Cys)-(β-Ala)₂-Tyr-Gly-(Arg)₅-Gln- (Arg)₃-NH₂; (SEQ ID NO: 213) D-Phe-c(Cys-His-D-(Et)Tyr-Arg-Trp-β-Ala-D-Cys)-(β-Ala)₂-(Arg)₅-Gln-(Arg)₃-NH₂; (SEQ ID NO: 213) D-Phe-c(Cys-His-D-(Et)Tyr-Arg-Trp-β-Ala-D-Cys)-(β-Ala)₂-Gly-(Arg)₅-Gln-(Arg)₃- NH₂; (SEQ ID NO: 267) D-Phe-c(Cys-His-D-(Et)Tyr-Arg-Trp-β-Ala-D-Cys)-(β-Ala)₂-(Arg)₅-Gln-(Arg)₄-NH₂; (SEQ ID NO: 214) D-Phe-c(Cys-His-D-(Et)Tyr-Arg-Trp-β-Ala-D-Cys)-Doc-Tyr-Gly-(Arg)₅-Gln-(Arg)₃- NH₂; (SEQ ID NO: 216) D-Phe-c(Cys-His-D-(Et)Tyr-Arg-Trp-β-Ala-D-Cys)-Doc-(Arg)₅-Gln-(Arg)₃-NH₂; (SEQ ID NO: 214) D-Phe-c(Cys-His-D-(Et)Tyr-Arg-Trp-β-Ala-D-Cys)-Doc-Gly-(Arg)₅-Gln-(Arg)₃-NH₂; (SEQ ID NO: 217) D-Phe-c(Cys-His-D-(Et)Tyr-Arg-Trp-β-Ala-D-Cys)-Doc-(Arg)₅-Gln-(Arg)₄-NH₂; (SEQ ID NO: 215) D-Phe-c(Cys-His-D-(Et)Tyr-Arg-Trp-β-Ala-D-Cys)-(Doc)₂-Tyr-Gly-(Arg)₅-Gln-(Arg)₃- NH₂; (SEQ ID NO: 216) D-Phe-c(Cys-His-D-(Et)Tyr-Arg-Trp-β-Ala-D-Cys)-(Doc)₂-(Arg)₅-Gln-(Arg)₃-NH₂; (SEQ ID NO: 215) D-Phe-c(Cys-His-D-(Et)Tyr-Arg-Trp-β-Ala-D-Cys)-(Doc)₂-Gly-(Arg)₅-Gln-(Arg)₃- NH₂; (SEQ ID NO: 217) D-Phe-c(Cys-His-D-(Et)Tyr-Arg-Trp-β-Ala-D-Cys)-(Doc)₂-(Arg)₅-Gln-(Arg)₄-NH₂; (SEQ ID NO: 218) D-Phe-c(Cys-His-D-(Et)Tyr-hArg-Trp-β-Ala-D-Cys)-Thr-β-Ala-Tyr-Gly-(Arg)₅-Gln- (Arg)₃-NH₂; (SEQ ID NO: 219) D-Phe-c(Cys-His-D-(Et)Tyr-hArg-Trp-β-Ala-D-Cys)-Thr-β-Ala-(Arg)₅-Gln-(Arg)₃- NH₂; (SEQ ID NO: 218) D-Phe-c(Cys-His-D-(Et)Tyr-hArg-Trp-β-Ala-D-Cys)-Thr-(β-Ala)₂-Tyr-Gly-(Arg)₅-Gln- (Arg)₃-NH₂; (SEQ ID NO: 219) D-Phe-c(Cys-His-D-(Et)Tyr-hArg-Trp-β-Ala-D-Cys)-Thr-(β-Ala)₂-(Arg)₅-Gln-(Arg)₃- NH₂; (SEQ ID NO: 221) D-Phe-c(Cys-His-D-(Et)Tyr-hArg-Trp-β-Ala-D-Cys)-Thr-Doc-Tyr-Gly-(Arg)₅-Gln- (Arg)₃-NH₂; (SEQ ID NO: 220) D-Phe-c(Cys-His-D-(Et)Tyr-hArg-Trp-β-Ala-D-Cys)-Thr-Doc-(Arg)₅-Gln-(Arg)₃-NH₂; (SEQ ID NO: 221) D-Phe-c(Cys-His-D-(Et)Tyr-hArg-Trp-β-Ala-D-Cys)-Thr-(Doc)₂-Tyr-Gly-(Arg)₅-Gln- (Arg)₃-NH₂; (SEQ ID NO: 222) D-Phe-c(Cys-His-D-(Et)Tyr-hArg-Trp-β-Ala-D-Cys)-Thr-β-Ala-Tyr-Gly-(Arg)₅-Gln- (Arg)₄-NH₂; (SEQ ID NO: 223) D-Phe-c(Cys-His-D-(Et)Tyr-hArg-Trp-β-Ala-D-Cys)-Thr-β-Ala-(Arg)₅-Gln-(Arg)₄- NH₂; (SEQ ID NO: 222) D-Phe-c(Cys-His-D-(Et)Tyr-hArg-Trp-β-Ala-D-Cys)-Thr-(β-Ala)₂-Tyr-Gly-(Arg)₅-Gln- (Arg)₄-NH₂; (SEQ ID NO: 223) D-Phe-c(Cys-His-D-(Et)Tyr-hArg-Trp-β-Ala-D-Cys)-Thr-(β-Ala)₂-(Arg)₅-Gln-(Arg)₄- NH₂; (SEQ ID NO: 224) D-Phe-c(Cys-His-D-(Et)Tyr-hArg-Trp-β-Ala-D-Cys)-Thr-Doc-Tyr-Gly-(Arg)₅-Gln- (Arg)₄-NH₂; (SEQ ID NO: 225) D-Phe-c(Cys-His-D-(Et)Tyr-hArg-Trp-β-Ala-D-Cys)-Thr-Doc-(Arg)₅-Gln-(Arg)₄-NH₂; (SEQ ID NO: 224) D-Phe-c(Cys-His-D-(Et)Tyr-hArg-Trp-β-Ala-D-Cys)-Thr-(Doc)₂-Tyr-Gly-(Arg)₅-Gln- (Arg)₄-NH₂; (SEQ ID NO: 225) D-Phe-c(Cys-His-D-(Et)Tyr-hArg-Trp-β-Ala-D-Cys)-Thr-(Doc)₂-(Arg)₅-Gln-(Arg)₄- NH₂; (SEQ ID NO: 227) D-Phe-c(Cys-His-D-(Et)Tyr-hArg-Bip-β-Ala-D-Cys)-Thr-β-Ala-Tyr-Gly-(Arg)₅-Gln- (Arg)₃-NH₂; (SEQ ID NO: 226) D-Phe-c(Cys-His-D-(Et)Tyr-hArg-Bip-β-Ala-D-Cys)-Thr-β-Ala-Tyr-Gly-(Arg)₅-Gln- (Arg)₄-NH₂; (SEQ ID NO: 228) D-Phe-c(Cys-His-D-(Et)Tyr-hArg-Bip-β-Ala-D-Cys)-Thr-β-Ala-(Arg)₅-Gln-(Arg)₃- NH₂; (SEQ ID NO: 227) D-Phe-c(Cys-His-D-(Et)Tyr-hArg-Bip-β-Ala-D-Cys)-Thr-(β-Ala)₂-Tyr-Gly-(Arg)₅-Gln- (Arg)₃-NH₂; (SEQ ID NO: 228) D-Phe-c(Cys-His-D-(Et)Tyr-hArg-Bip-β-Ala-D-Cys)-Thr-(β-Ala)₂-(Arg)₅-Gln-(Arg)₃- NH₂; (SEQ ID NO: 229) D-Phe-c(Cys-His-D-(Et)Tyr-hArg-Bip-β-Ala-D-Cys)-Thr-Doc-Tyr-Gly-(Arg)₅-Gln- (Arg)₃-NH₂; (SEQ ID NO: 230) D-Phe-c(Cys-His-D-(Et)Tyr-hArg-Bip-β-Ala-D-Cys)-Thr-Doc-Tyr-Gly-(Arg)₅-Gln- (Arg)₄-NH₂; (SEQ ID NO: 232) D-Phe-c(Cys-His-D-(Et)Tyr-hArg-Bip-β-Ala-D-Cys)-Thr-Doc-(Arg)₅-Gln-(Arg)₃-NH₂; (SEQ ID NO: 231) D-Phe-c(Cys-His-D-(Et)Tyr-hArg-Bip-β-Ala-D-Cys)-Thr-(Doc)₂-Tyr-Gly-(Arg)₅-Gln- (Arg)₃-NH₂; (SEQ ID NO: 232) D-Phe-c(Cys-His-D-(Et)Tyr-hArg-Bip-β-Ala-D-Cys)-Thr-(Doc)₂-(Arg)₅-Gln-(Arg)₃- NH₂; (SEQ ID NO: 233) Ac-Nle-c(Cys-D-Ala-His-D-Phe-Arg-Trp-Gly-Cys)-β-Ala-Tyr-Gly-(Arg)₅-Gln-(Arg)₃- NH₂; (SEQ ID NO: 234) Ac-Nle-c(Cys-D-Ala-His-D-Phe-Arg-Trp-Gly-Cys)-β-Ala-(Arg)₅-Gln-(Arg)₃-NH₂; (SEQ ID NO: 235) Nle-c(Cys-His-D-Phe-Arg-Trp-Apn-Cys)-β-Ala-Tyr-Gly-(Arg)₅-Gln-(Arg)₃-NH₂; (SEQ ID NO: 236) Nle-c(Cys-His-D-Phe-Arg-Trp-Apn-Cys)-β-Ala-(Arg)₅-Gln-(Arg)₃-NH₂; (SEQ ID NO: 235) Nle-c(Cys-His-D-Phe-Arg-Trp-Apn-Cys)-(β-Ala)₂-Tyr-Gly-(Arg)₅-Gln-(Arg)₃-NH₂; (SEQ ID NO: 236) Nle-c(Cys-His-D-Phe-Arg-Trp-Apn-Cys)-(β-Ala)₂-(Arg)₅-Gln-(Arg)₃-NH₂; (SEQ ID NO: 237) Nle-c(Cys-His-D-Phe-Arg-Trp-Apn-Cys)-β-Ala-Tyr-Gly-(Arg)₅-Gln-(Arg)₄-NH₂; (SEQ ID NO: 238) Nle-c(Cys-His-D-Phe-Arg-Trp-Apn-Cys)-β-Ala-(Arg)₅-Gln-(Arg)₄-NH₂; (SEQ ID NO: 237) Nle-c(Cys-His-D-Phe-Arg-Trp-Apn-Cys)-(β-Ala)₂-Tyr-Gly-(Arg)₅-Gln-(Arg)₄-NH₂; (SEQ ID NO: 238) Nle-c(Cys-His-D-Phe-Arg-Trp-Apn-Cys)-(β-Ala)₂-(Arg)₅-Gln-(Arg)₄-NH₂; (SEQ ID NO: 239) Nle-c(Cys-His-D-Phe-Arg-Trp-Apn-Cys)-Doc-Tyr-Gly-(Arg)₅-Gln-(Arg)₃-NH₂; (SEQ ID NO: 240) Nle-c(Cys-His-D-Phe-Arg-Trp-Apn-Cys)-Doc-(Arg)₅-Gln-(Arg)₃-NH₂; (SEQ ID NO: 239) Nle-c(Cys-His-D-Phe-Arg-Trp-Apn-Cys)-(Doc)₂-Tyr-Gly-(Arg)₅-Gln-(Arg)₃-NH₂; (SEQ ID NO: 240) Nle-c(Cys-His-D-Phe-Arg-Trp-Apn-Cys)-(Doc)₂-(Arg)₅-Gln-(Arg)₃-NH₂; (SEQ ID NO: 241) Nle-c(Cys-His-D-Phe-Arg-Trp-Apn-Cys)-Doc-Tyr-Gly-(Arg)₅-Gln-(Arg)₄-NH₂; (SEQ ID NO: 242) Nle-c(Cys-His-D-Phe-Arg-Trp-Apn-Cys)-Doc-(Arg)₅-Gln-(Arg)₄-NH₂; (SEQ ID NO: 241) Nle-c(Cys-His-D-Phe-Arg-Trp-Apn-Cys)-(Doc)₂-Tyr-Gly-(Arg)₅-Gln-(Arg)₄-NH₂; (SEQ ID NO: 242) Nle-c(Cys-His-D-Phe-Arg-Trp-Apn-Cys)-(Doc)₂-(Arg)₅-Gln-(Arg)₄-NH₂; (SEQ ID NO: 243) Ac-Nle-c(Cys-D-Leu-His-D-Phe-Arg-Trp-Cys)-β-Ala-Tyr-Gly-(Arg)₅-Gln-(Arg)₃-NH₂; (SEQ ID NO: 244) Ac-Nle-c(Cys-D-Leu-His-D-Phe-Arg-Trp-Cys)-β-Ala-(Arg)₅-Gln-(Arg)₃-NH₂; (SEQ ID NO: 243) Ac-Nle-c(Cys-D-Leu-His-D-Phe-Arg-Trp-Cys)-(β-Ala)₂-Tyr-Gly-(Arg)₅-Gln-(Arg)₃- NH₂; (SEQ ID NO: 244) Ac-Nle-c(Cys-D-Leu-His-D-Phe-Arg-Trp-Cys)-(β-Ala)₂-(Arg)₅-Gln-(Arg)₃-NH₂; (SEQ ID NO: 245) Ac-Nle-c(Cys-D-Leu-His-D-Phe-Arg-Trp-Cys)-Doc-Tyr-Gly-(Arg)₅-Gln-(Arg)₃-NH₂; (SEQ ID NO: 246) Ac-Nle-c(Cys-D-Leu-His-D-Phe-Arg-Trp-Cys)-Doc-(Arg)₅-Gln-(Arg)₃-NH₂; (SEQ ID NO: 245) Ac-Nle-c(Cys-D-Leu-His-D-Phe-Arg-Trp-Cys)-(Doc)₂-Tyr-Gly-(Arg)₅-Gln-(Arg)₃- NH₂; (SEQ ID NO: 246) Ac-Nle-c(Cys-D-Leu-His-D-Phe-Arg-Trp-Cys)-(Doc)₂-(Arg)₅-Gln-(Arg)₃-NH₂; (SEQ ID NO: 247) Ac-Nle-c(Cys-D-Leu-His-D-Phe-Arg-Trp-Cys)-β-Ala-Tyr-Gly-(Arg)₅-Gln-(Arg)₄-NH₂; (SEQ ID NO: 248) Ac-Nle-c(Cys-D-Leu-His-D-Phe-Arg-Trp-Cys)-β-Ala-(Arg)₅-Gln-(Arg)₄-NH₂; (SEQ ID NO: 247) Ac-Nle-c(Cys-D-Leu-His-D-Phe-Arg-Trp-Cys)-(β-Ala)₂-Tyr-Gly-(Arg)₅-Gln-(Arg)₄- NH₂; (SEQ ID NO: 248) Ac-Nle-c(Cys-D-Leu-His-D-Phe-Arg-Trp-Cys)-(β-Ala)₂-(Arg)₅-Gln-(Arg)₄-NH₂; (SEQ ID NO: 249) Ac-Nle-c(Cys-D-Leu-His-D-Phe-Arg-Trp-Cys)-Doc-Tyr-Gly-(Arg)₅-Gln-(Arg)₄-NH₂; (SEQ ID NO: 250) Ac-Nle-c(Cys-D-Leu-His-D-Phe-Arg-Trp-Cys)-Doc-(Arg)₅-Gln-(Arg)₄-NH₂; (SEQ ID NO: 249) Ac-Nle-c(Cys-D-Leu-His-D-Phe-Arg-Trp-Cys)-(Doc)₂-Tyr-Gly-(Arg)₅-Gln-(Arg)₄- NH₂; (SEQ ID NO: 250) Ac-Nle-c(Cys-D-Leu-His-D-Phe-Arg-Trp-Cys)-(Doc)₂-(Arg)₅-Gln-(Arg)₄-NH₂; (SEQ ID NO: 251) Ac-Nle-c(Cys-D-Cha-His-D-Phe-Arg-Trp-Cys)-β-Ala-Tyr-Gly-(Arg)₅-Gln-(Arg)₃-NH₂; (SEQ ID NO: 252) Ac-Nle-c(Cys-D-Cha-His-D-Phe-Arg-Trp-Cys)-β-Ala-(Arg)₅-Gln-(Arg)₃-NH₂; (SEQ ID NO: 251) Ac-Nle-c(Cys-D-Cha-His-D-Phe-Arg-Trp-Cys)-(β-Ala)₂-Tyr-Gly-(Arg)₅-Gln-(Arg)₃- NH₂; (SEQ ID NO: 252) Ac-Nle-c(Cys-D-Cha-His-D-Phe-Arg-Trp-Cys)-(β-Ala)₂-(Arg)₅-Gln-(Arg)₃-NH₂; (SEQ ID NO: 253) Ac-Nle-c(Cys-D-Cha-His-D-Phe-Arg-Trp-Cys)-Doc-Tyr-Gly-(Arg)₅-Gln-(Arg)₃-NH₂; (SEQ ID NO: 254) Ac-Nle-c(Cys-D-Cha-His-D-Phe-Arg-Trp-Cys)-Doc-(Arg)₅-Gln-(Arg)₃-NH₂; (SEQ ID NO: 253) Ac-Nle-c(Cys-D-Cha-His-D-Phe-Arg-Trp-Cys)-(Doc)₂-Tyr-Gly-(Arg)₅-Gln-(Arg)₃- NH₂; (SEQ ID NO: 254) Ac-Nle-c(Cys-D-Cha-His-D-Phe-Arg-Trp-Cys)-(Doc)₂-(Arg)₅-Gln-(Arg)₃-NH₂; (SEQ ID NO: 255) Ac-Nle-c(Cys-D-Cha-His-D-Phe-Arg-Trp-Cys)-β-Ala-Tyr-Gly-(Arg)₅-Gln-(Arg)₄-NH₂; (SEQ ID NO: 256) Ac-Nle-c(Cys-D-Cha-His-D-Phe-Arg-Trp-Cys)-β-Ala-(Arg)₅-Gln-(Arg)₄-NH₂; (SEQ ID NO: 255) Ac-Nle-c(Cys-D-Cha-His-D-Phe-Arg-Trp-Cys)-(β-Ala)₂-Tyr-Gly-(Arg)₅-Gln-(Arg)₄- NH₂; (SEQ ID NO: 256) Ac-Nle-c(Cys-D-Cha-His-D-Phe-Arg-Trp-Cys)-(β-Ala)₂-(Arg)₅-Gln-(Arg)₄-NH₂; (SEQ ID NO: 257) Ac-Nle-c(Cys-D-Cha-His-D-Phe-Arg-Trp-Cys)-Doc-Tyr-Gly-(Arg)₅-Gln-(Arg)₄-NH₂; (SEQ ID NO: 258) Ac-Nle-c(Cys-D-Cha-His-D-Phe-Arg-Trp-Cys)-Doc-(Arg)₅-Gln-(Arg)₄-NH₂; (SEQ ID NO: 257) Ac-Nle-c(Cys-D-Cha-His-D-Phe-Arg-Trp-Cys)-(Doc)₂-Tyr-Gly-(Arg)₅-Gln-(Arg)₄- NH₂; (SEQ ID NO: 258) Ac-Nle-c(Cys-D-Cha-His-D-Phe-Arg-Trp-Cys)-(Doc)₂-(Arg)₅-Gln-(Arg)₄-NH₂; (SEQ ID NO: 259) Nle-c(Cys-His-D-Phe-Arg-Trp-Gaba-Cys)-β-Ala-Tyr-Gly-(Arg)₅-Gln-(Arg)₃-NH₂; (SEQ ID NO: 260) Nle-c(Cys-His-D-Phe-Arg-Trp-Gaba-Cys)-β-Ala-(Arg)₅-Gln-(Arg)₃-NH₂; (SEQ ID NO: 259) Nle-c(Cys-His-D-Phe-Arg-Trp-Gaba-Cys)-(β-Ala)₂-Tyr-Gly-(Arg)₅-Gln-(Arg)₃-NH₂; (SEQ ID NO: 260) Nle-c(Cys-His-D-Phe-Arg-Trp-Gaba-Cys)-(β-Ala)₂-(Arg)₅-Gln-(Arg)₃-NH₂; (SEQ ID NO: 261) Nle-c(Cys-His-D-Phe-Arg-Trp-Gaba-Cys)-β-Ala-Tyr-Gly-(Arg)₅-Gln-(Arg)₄-NH₂; (SEQ ID NO: 262) Nle-c(Cys-His-D-Phe-Arg-Trp-Gaba-Cys)-β-Ala-(Arg)₅-Gln-(Arg)₄-NH₂; (SEQ ID NO: 261) Nle-c(Cys-His-D-Phe-Arg-Trp-Gaba-Cys)-(β-Ala)₂-Tyr-Gly-(Arg)₅-Gln-(Arg)₄-NH₂; (SEQ ID NO: 262) Nle-c(Cys-His-D-Phe-Arg-Trp-Gaba-Cys)-(β-Ala)₂-(Arg)₅-Gln-(Arg)₄-NH₂; (SEQ ID NO: 263) Nle-c(Cys-His-D-Phe-Arg-Trp-Gaba-Cys)-Doc-Tyr-Gly-(Arg)₅-Gln-(Arg)₃-NH₂; (SEQ ID NO: 264) Nle-c(Cys-His-D-Phe-Arg-Trp-Gaba-Cys)-Doc-(Arg)₅-Gln-(Arg)₃-NH₂; (SEQ ID NO: 263) Nle-c(Cys-His-D-Phe-Arg-Trp-Gaba-Cys)-(Doc)₂-Tyr-Gly-(Arg)₅-Gln-(Arg)₃-NH₂; (SEQ ID NO: 264) Nle-c(Cys-His-D-Phe-Arg-Trp-Gaba-Cys)-(Doc)₂-(Arg)₅-Gln-(Arg)₃-NH₂; (SEQ ID NO: 265) Nle-c(Cys-His-D-Phe-Arg-Trp-Gaba-Cys)-Doc-Tyr-Gly-(Arg)₅-Gln-(Arg)₄-NH₂; (SEQ ID NO: 266) Nle-c(Cys-His-D-Phe-Arg-Trp-Gaba-Cys)-Doc-(Arg)₅-Gln-(Arg)₄-NH₂; (SEQ ID NO: 265) Nle-c(Cys-His-D-Phe-Arg-Trp-Gaba-Cys)-(Doc)₂-Tyr-Gly-(Arg)₅-Gln-(Arg)₄-NH₂; (SEQ ID NO: 266) Nle-c(Cys-His-D-Phe-Arg-Trp-Gaba-Cys)-(Doc)₂-(Arg)₅-Gln-(Arg)₄-NH₂; (SEQ ID NO: 268) Ac-c(Cys-Glu-His-D-4-Br-Phe-Arg-Trp-Gly-Cys)-(Pro)₂-Lys-Asp-NH₂; (SEQ ID NO: 269) Ac-c(Cys-Glu-His-D-2-Nal-Arg-Trp-Ala-Cys)-(Pro)₂-Lys-Asp-NH₂; (SEQ ID NO: 269) Ac-c(Cys-Glu-His-D-2-Nal-Arg-2-Nal-Ala-Cys)-(Pro)₂-Lys-Asp-NH₂; (SEQ ID NO: 269) Ac-c(Cys-Glu-His-D-2-Nal-Arg-1-Nal-Ala-Cys)-(Pro)₂-Lys-Asp-NH₂; (SEQ ID NO: 269) Ac-c(Cys-Glu-His-D-2-Nal-Arg-Bal-Ala-Cys)-(Pro)₂-Lys-Asp-NH₂; (SEQ ID NO: 270) Ac-c(Cys-Glu-His-D-2-Nal-Arg-2-Nal-β-Ala-Cys)-(Pro)₂-Lys-Asp-NH₂; (SEQ ID NO: 270) Ac-c(Cys-Glu-His-D-2-Nal-Arg-2-Nal-Aib-Cys)-(Pro)₂-Lys-Asp-NH₂; (SEQ ID NO: 271) c[Hydantoin(C(O)-(Cys-D-Ala))-His-D-Phe-Arg-Trp-Cys]-NH₂; (SEQ ID NO: 271) c[Hydantoin(C(O)-(hCys-D-Ala))-His-D-Phe-Arg-Trp-Cys]-NH₂; (SEQ ID NO: 272) c[Hydantoin(C(O)-(Cys-D-Ala))-His-D-2-Nal-Arg-Trp-Cys]-NH₂; (SEQ ID NO: 272) c[Hydantoin(C(O)-(hCys-D-Ala))-His-D-2-Nal-Arg-Trp-Cys]-NH₂; (SEQ ID NO: 273) c[Hydantoin(C(O)-(Asp-D-Ala))-His-D-Phe-Arg-Trp-Lys]-NH₂; (SEQ ID NO: 273) c[Hydantoin(C(O)-(Asp-D-Ala))-His-D-Phe-Arg-Trp-Orn]-NH₂; (SEQ ID NO: 273) c[Hydantoin(C(O)-(Asp-D-Ala))-His-D-Phe-Arg-Trp-Dab]-NH₂; (SEQ ID NO: 273) c[Hydantoin(C(O)-(Asp-D-Ala))-His-D-Phe-Arg-Trp-Dap]-NH₂; (SEQ ID NO: 275) c[Hydantoin(C(O)-(Asp-His))-D-2-Nal-Arg-Trp-Lys]-NH₂; (SEQ ID NO: 274) c[Hydantoin(C(O)-(Asp-His))-D-Phe-Arg-Trp-Lys]-NH₂; (SEQ ID NO: 274) c[Hydantoin(C(O)-(Asp-A3c))-D-Phe-Arg-Trp-Lys]-NH₂; (SEQ ID NO: 274) c[Hydantoin(C(O)-(Asp-A5c))-D-Phe-Arg-Trp-Lys]-NH₂; (SEQ ID NO: 274) c[Hydantoin(C(O)-(Asp-A6c))-D-Phe-Arg-Trp-Lys]-NH₂; (SEQ ID NO: 275) c[Hydantoin(C(O)-(Asp-A3c))-D-2-Nal-Arg-Trp-Lys]-NH₂; (SEQ ID NO: 275) c[Hydantoin(C(O)-(Asp-A5c))-D-2-Nal-Arg-Trp-Lys]-NH₂; (SEQ ID NO: 275) c[Hydantoin(C(O)-(Asp-A6c))-D-2-Nal-Arg-Trp-Lys]-NH₂; (SEQ ID NO: 275) c[Hydantoin (C(O)-(Asp-A5c))-D-2-Nal-Arg-Trp-Lys]-NH₂; (SEQ ID NO: 274) c[Hydantoin(C(O)-(Asp-Aic))-D-Phe-Arg-Trp-Lys]-NH₂; (SEQ ID NO: 274) c[Hydantoin(C(O)-(Asp-Apc))-D-Phe-Arg-Trp-Lys]-NH₂; (SEQ ID NO: 275) c[Hydantoin(C(O)-(Asp-Aic))-D-2-Nal-Arg-Trp-Lys]-NH₂; (SEQ ID NO: 275) c[Hydantoin(C(O)-(Asp-Apc))-D-2-Nal-Arg-Trp-Lys]-NH₂; (SEQ ID NO: 275) c[Hydantoin-(C(O)-(Asp-Aic))-D-2-Nal-Arg-Trp-Lys]-NH₂; (SEQ ID NO: 275) c[Hydantoin-(C(O)-(Asp-Apc))-D-2-Nal-Arg-Trp-Lys]-NH₂; (SEQ ID NO: 276) c[Hydantoin(C(O)-(Glu-D-Ala))-His-D-Phe-Arg-Trp-Orn]-NH₂; (SEQ ID NO: 276) c[Hydantoin(C(O)-(Glu-D-Ala))-His-D-Phe-Arg-Trp-Dab]-NH₂; (SEQ ID NO: 276) c[Hydantoin(C(O)-(Glu-D-Ala))-His-D-Phe-Arg-Trp-Dap]-NH₂; (SEQ ID NO: 277) c[Hydantoin(C(O)-(Glu-His))-D-Phe-Arg-Trp-Dap]-NH₂; (SEQ ID NO: 278) Hydantoin(C(O)-(Arg-Gly))-c(Cys-Glu-His-D-Phe-Arg-Trp-Cys)-NH₂; (SEQ ID NO: 278) Hydantoin(C(O)-(Nle-Gly))-c(Cys-Glu-His-D-Phe-Arg-Trp-Cys)-NH₂; (SEQ ID NO: 278) Hydantoin(C(O)-(Gly-Gly))-c(Cys-Glu-His-D-Phe-Arg-Trp-Cys)-NH₂; (SEQ ID NO: 279) Hydantoin(C(O)-(Nle-Gly))-c(Cys-D-Ala-His-D-Phe-Arg-Trp-Cys)-NH₂; (SEQ ID NO: 279) Hydantoin(C(O)-(Gly-Gly))-c(Cys-D-Ala-His-D-Phe-Arg-Trp-Cys)-NH₂; (SEQ ID NO: 280) Hydantoin(C(O)-(Nle-Gly))-c(Cys-D-Ala-His-D-Phe-Arg-Trp-Pen)-NH₂; (SEQ ID NO: 280) Hydantoin(C(O)-(Gly-Gly))-c(Cys-D-Ala-His-D-Phe-Arg-Trp-Pen)-NH₂; (SEQ ID NO: 279) Hydantoin(C(O)-(Ala-Gly))-c(Cys-D-Ala-His-D-Phe-Arg-Trp-Cys)-NH₂; (SEQ ID NO: 279) Hydantoin(C(O)-(D-Ala-Gly))-c(Cys-D-Ala-His-D-Phe-Arg-Trp-Cys)-NH₂; (SEQ ID NO: 279) Hydantoin(C(O)-(Aib-Gly))-c(Cys-D-Ala-His-D-Phe-Arg-Trp-Cys)-NH₂; (SEQ ID NO: 279) Hydantoin(C(O)-(Val-Gly))-c(Cys-D-Ala-His-D-Phe-Arg-Trp-Cys)-NH₂; (SEQ ID NO: 279) Hydantoin(C(O)-(Ile-Gly))-c(Cys-D-Ala-His-D-Phe-Arg-Trp-Cys)-NH₂; (SEQ ID NO: 279) Hydantoin(C(O)-(Leu-Gly))-c(Cys-D-Ala-His-D-Phe-Arg-Trp-Cys)-NH₂; (SEQ ID NO: 281) Hydantoin(C(O)-(Gly-Gly))-c(Cys-Glu-His-D-2-Nal-Arg-Trp-Cys)-NH₂; (SEQ ID NO: 281) Hydantoin(C(O)-(Nle-Gly))-c(Cys-Glu-His-D-2-Nal-Arg-Trp-Cys)-NH₂; (SEQ ID NO: 278) Hydantoin(C(O)-(D-Arg-Gly))-c(Cys-Glu-His-D-Phe-Arg-Trp-Cys)-NH₂; (SEQ ID NO: 279) Hydantoin(C(O)-(D-Arg-Gly))-c(Cys-D-Ala-His-D-Phe-Arg-Trp-Cys)-NH₂; (SEQ ID NO: 279) Hydantoin(C(O)-(Arg-Gly))-c(Cys-D-Ala-His-D-Phe-Arg-Trp-Cys)-NH₂; (SEQ ID NO: 282) Hydantoin(C(O)-(D-Arg-Gly))-c(Cys-D-Ala-His-D-2-Nal-Arg-Trp-Cys)-NH₂; (SEQ ID NO: 282) Hydantoin(C(O)-(Arg-Gly))-c(Cys-D-Ala-His-D-2-Nal-Arg-Trp-Cys)-NH₂; (SEQ ID NO: 283) Hydantoin(C(O)-(Ala-Nle))-c(Cys-Glu-His-D-Phe-Arg-Trp-Cys)-NH₂; (SEQ ID NO: 283) Hydantoin(C(O)-(Val-Nle))-c(Cys-Glu-His-D-Phe-Arg-Trp-Cys)-NH₂; (SEQ ID NO: 283) Hydantoin(C(O)-(Gly-Nle))-c(Cys-Glu-His-D-Phe-Arg-Trp-Cys)-NH₂; (SEQ ID NO: 284) Hydantoin(C(O)-(A6c-Nle))-c(Cys-D-Ala-His-D-Phe-Arg-Trp-Cys)-NH₂; (SEQ ID NO: 284) Hydantoin(C(O)-(Gly-Nle))-c(Cys-D-Ala-His-D-Phe-Arg-Trp-Cys)-NH₂; (SEQ ID NO: 284) Hydantoin(C(O)-(Ala-Nle))-c(Cys-D-Ala-His-D-Phe-Arg-Trp-Cys)-NH₂; (SEQ ID NO: 284) Hydantoin(C(O)-(D-Ala-Nle))-c(Cys-D-Ala-His-D-Phe-Arg-Trp-Cys)-NH₂; (SEQ ID NO: 284) Hydantoin(C(O)-(Val-Nle))-c(Cys-D-Ala-His-D-Phe-Arg-Trp-Cys)-NH₂; (SEQ ID NO: 284) Hydantoin(C(O)-(Leu-Nle))-c(Cys-D-Ala-His-D-Phe-Arg-Trp-Cys)-NH₂; (SEQ ID NO: 284) Hydantoin(C(O)-(Cha-Nle))-c(Cys-D-Ala-His-D-Phe-Arg-Trp-Cys)-NH₂; (SEQ ID NO: 284) Hydantoin(C(O)-(Aib-Nle))-c(Cys-D-Ala-His-D-Phe-Arg-Trp-Cys)-NH₂; (SEQ ID NO: 285) Hydantoin(C(O)-(Gly-Arg))-c(Cys-Glu-His-D-Phe-Arg-Trp-Cys)-NH₂; (SEQ ID NO: 285) Hydantoin(C(O)-(Gly-Arg))-c(Cys-Glu-His-D-2-Nal-Arg-Trp-Cys)-NH₂; (SEQ ID NO: 286) Hydantoin(C(O)-(Gly-Arg))-c(Cys-D-Ala-His-D-Phe-Arg-Trp-Cys)-NH₂; (SEQ ID NO: 286) Hydantoin(C(O)-(Gly-Arg))-c(Cys-D-Ala-His-D-2-Nal-Arg-Trp-Cys)-NH₂; (SEQ ID NO: 287) Hydantoin(C(O)-(Gly-D-Arg))-c(Cys-Glu-His-D-Phe-Arg-Trp-Cys)-NH₂; (SEQ ID NO: 288) Hydantoin(C(O)-(Gly-D-Arg))-c(Cys-D-Ala-His-D-Phe-Arg-Trp-Cys)-NH₂; (SEQ ID NO: 288) Hydantoin(C(O)-(Gly-D-Arg))-c(Cys-D-Ala-His-D-2-Nal-Arg-Trp-Cys)-NH₂; (SEQ ID NO: 289) Hydantoin(C(O)-(Nle-Ala))-c(Cys-Glu-His-D-Phe-Arg-Trp-Cys)-NH₂; (SEQ ID NO: 290) c[Hydantoin(C(O)-(Ala-Cys))-D-Ala-His-D-Phe-Arg-Trp-Cys]-NH₂, (SEQ ID NO: 290) c[Hydantoin(C(O)-(Nle-Cys))-D-Ala-His-D-Phe-Arg-Trp-Cys]-NH₂; (SEQ ID NO: 290) c[Hydantoin(C(O)-(D-Ala-Cys))-D-Ala-His-D-Phe-Arg-Trp-Cys]-NH₂; (SEQ ID NO: 290) c[Hydantoin(C(O)-(Aib-Cys))-D-Ala-His-D-Phe-Arg-Trp-Cys]-NH₂; (SEQ ID NO: 290) c[Hydantoin(C(O)-(Val-Cys))-D-Ala-His-D-Phe-Arg-Trp-Cys]-NH₂; (SEQ ID NO: 290) c[Hydantoin(C(O)-(Abu-Cys))-D-Ala-His-D-Phe-Arg-Trp-Cys]-NH₂; (SEQ ID NO: 290) c[Hydantoin(C(O)-(Leu-Cys))-D-Ala-His-D-Phe-Arg-Trp-Cys]-NH₂; (SEQ ID NO: 290) c[Hydantoin(C(O)-(Ile-Cys))-D-Ala-His-D-Phe-Arg-Trp-Cys]-NH₂; (SEQ ID NO: 290) c[Hydantoin(C(O)-(Cha-Cys))-D-Ala-His-D-Phe-Arg-Trp-Cys]-NH₂; (SEQ ID NO: 290) c[Hydantoin(C(O)-(A6c-Cys))-D-Ala-His-D-Phe-Arg-Trp-Cys]-NH₂; (SEQ ID NO: 290) c[Hydantoin(C(O)-(Phe-Cys))-D-Ala-His-D-Phe-Arg-Trp-Cys]-NH₂; (SEQ ID NO: 290) c[Hydantoin(C(O)-(Gly-Cys))-D-Ala-His-D-Phe-Arg-Trp-Cys]-NH₂; (SEQ ID NO: 291) c[Hydantoin(C(O)-(Gly-Cys))-Glu-His-D-Phe-Arg-Trp-Cys]-NH₂; (SEQ ID NO: 292) Ac-Tyr-Arg-c(Cys-D-Ala-His-D-Phe-Arg-Trp-Cys)-NH₂; (SEQ ID NO: 292) Ac-2-Nal-Arg-c(Cys-D-Ala-His-D-Phe-Arg-Trp-Cys)-NH₂; (SEQ ID NO: 292) Ac-1-Nal-Arg-c(Cys-D-Ala-His-DPhe-Arg-Trp-Cys)-NH₂; (SEQ ID NO: 292) Ac-Phe-Arg-c(Cys-D-Ala-His-D-Phe-Arg-Trp-Cys)-NH₂; (SEQ ID NO: 292) Ac-Trp-Arg-c(Cys-D-Ala-His-D-Phe-Arg-Trp-Cys)-NH₂; (SEQ ID NO: 292) Ac-Pff-Arg-c(Cys-D-Ala-His-D-Phe-Arg-Trp-Cys)-NH₂; (SEQ ID NO: 293) H-His-Arg-c(Cys-D-Ala-His-D-Phe-Arg-Trp-Cys)-NH₂; and (SEQ ID NO: 292) Ac-His-Arg-c(Cys-D-Ala-His-D-Phe-Arg-Trp-Cys)-NH₂; or a pharmaceutically acceptable salt thereof.

In one preferred aspect, the melanocortin receptor 4 agonist useful to treat insulin resistance in the subject in need thereof, is Ac-Arg-c(Cys-D-Ala-His-D-Phe-Arg-Trp-Cys)-NH₂ (SEQ ID NO:50) or a pharmaceutically acceptable salt thereof. In another preferred aspect, the melanocortin receptor 4 agonist useful to treat insulin resistance in the subject in need thereof, is Hydantoin(C(O)-(Arg-Gly))-c(Cys-Glu-His-D-Phe-Arg-Trp-Cys)-NH₂ (SEQ ID NO:278) or a pharmaceutically acceptable salt thereof.

In other aspects of the invention, administration of a compound or composition comprising a compound or pharmaceutical salt of a compound of the invention useful to treat insulin resistance, is continuous, hourly, four times daily, three time daily, twice daily, once daily, once every other day, twice weekly, once weekly, once every two weeks, once a month, or once every two months, or longer.

The subject in need of treatment may be obese, overweight, of normal weight or lean. The obese, overweight, normal weight or lean subject may suffer from type II diabetes. The preferred administration of a compound or composition comprising a compound or pharmaceutical salt of a compound of the invention useful to treat insulin resistance, is peripheral administration. Examples of peripheral administration include oral, subcutaneous, intraperitoneal, intramuscular, intravenous, rectal, transdermal or intranasal forms of administration.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1: Food consumed in fasted rats 6 hours after administration of 100 nmole/Kg of selected compounds.

FIG. 2A. Effect of subcutaneous administration of 75, 300 or 1200 nmole/kg/day of Compound A upon body weight in rats.

FIG. 2B. Effect of subcutaneous administration of 75, 300 or 1200 nmole/kg/day of Compound A upon cumulative food intake in rats.

FIG. 2C. Effect of subcutaneous administration of 75, 300 or 1200 nmole/kg/day of Compound A upon insulin levels in rats.

FIG. 2D. Effect of subcutaneous administration of 75, 300 or 1200 nmole/kg/day of Compound A upon glucose levels in rats.

FIG. 3A. Effect of subcutaneous administration of 75, 300 or 1200 nmole/kg/day of Compound B upon body weight in rats.

FIG. 3B. Effect of subcutaneous administration of 75, 300 or 1200 nmole/kg/day of

Compound B upon cumulative food intake in rats.

FIG. 3C. Effect of subcutaneous administration of 75, 300 or 1200 nmole/kg/day of Compound B upon insulin levels in rats.

FIG. 3D. Effect of subcutaneous administration of 75, 300 or 1200 nmole/kg/day of Compound B upon glucose levels in rats.

FIG. 4. Effect of subcutaneous administration of 200, 600 or 1800 nmole/kg/day of Compound A upon blood glucose levels in mice.

FIG. 5. Effect of intraperitoneal administration of 6.4 μmole/kg of Compound A upon blood glucose levels in obese mice.

DETAILED DESCRIPTION OF THE INVENTION

Recent studies have reported that staggering numbers of people world wide are overweight and suffering a wide variety of serious and expensive health problems. According the World Health Organization (as reported in Kouris-Blazos et al., Asia Pac. J. Clin. Nutr., 2007, 16:329-338), an estimated 1 billion people throughout the world are overweight and an estimated 300 million of these are obese. An estimated 22 million children under the age of 5 are severely overweight and in the European Union alone, the number of children who are overweight is expected to rise by 1.3 million children per year (Kosti et al., 2006, Cent. Eur. J. Public Health, 14:151-159). Obesity, as defined by the Statistical Bulletin provided by the Metropolitan Life Insurance Co., (1959, 40:1), is a condition in which a person is approximately 20-25% over normal body weight. Alternatively, an individual is considered obese if the person has a body mass index of greater than 25% over normal or greater than 30% over normal with risk factors (see Bray et al., Diabetes/Metabolism Review, 1988, 4:653-679 or Flynn et al., Proc. Nutritional Society, 1991, 50:413). One of the main causes for obesity is the consumption of a high caloric diet (Riccardi et al., Clin. Nutr., 2004, 23:447-456).

Diabetes is a chronic, debilitating disease afflicting many overweight and obese people. It is estimated that 20.8 million people in the United States alone have diabetes and more than 6 million more additional cases remain undiagnosed (Cornell, Manag. Care Pharm., 2007, 13:S11-5). Type 2 diabetes (also referred to herein as type II diabetes) is a chronic disease characterized by insulin resistance, impaired insulin secretion and hyperglycemia. Worldwide, type II diabetes is believed to affect approximately 171 million people, imparting numerous microvascular and macrovascular complications resulting in morbidity and mortality (Mudaliar, Indian J. Med. Res., 2007, 125:275-296). Mudaliar further notes that despite the availability of anti-hyperglycaemic agents available, control of glucose remains elusive in many patients.

Insulin resistance, also referred to as reduced insulin sensitivity, is a condition in which the amount of insulin needed to clear glucose from the blood of a subject is increased as compared to the amount of insulin needed to clear the same amount of glucose from the blood of a normal, non-insulin sensitive subject. Insulin resistance is regarded as the main link between obesity and type II diabetes (see Obici et al., J. Clin. Inv., 2001, 108:1079-1085 and references therein). It is known that rats fed a high fat diet show an increase in body weight (diet-induced obesity or DIO) and a decrease in insulin sensitivity. Such DIO rats provide an animal model in which to study the mechanisms of insulin resistance due to obesity (see for example Banno et al., FEBS letters, 2007, 581:1131-1136). The size and weight of adipose tissues are increased in DIO rats and it is thought that the accompanying hypertrophy of adipocytes leads to changes in the release of adipocytokines such as leptin and adiponectin which are known to regulate insulin sensitivity; it is thought that morphological changes in adipose tissue as well as changes in plasma levels of adipocytokines are among the causes of insulin resistance in DIO rats (summarized in Banno, et al., FEBS letters, 2007, 581:1131-1136 and references therein).

Melanocortins are proposed to play a large role in energy metabolism and homeostasis. Melanocortins cleaved from the POMC precursor exert their effects by binding to members of the melanocortin receptor family located in the brain. The major effect of melanocortin in the brain is to reduce food intake however, it has also been shown that melanocortin agonists or antagonists injected directly into the cerebral ventricle affect insulin actions in the periphery while food was withdrawn or while food intake was kept constant (see Schwartz et al., Nature, 2000, 404:661-671; Seeley et al., Ann. Rev. Nutr., 2004, 24:133-149; Cone et al., Recent Prog. Horm. Res., 1996, 51:287-317; Heijbor et al., Diabetologia, 2005, 48:1621-1626; Obici et al., J. Clin. Inv., 2001, 108:1079-1085). Taken together, these data suggest that central administration of melanocortins affects insulin sensitivity and may do so independently of energy balance. Banno et al., (FEBS letters, 2007, 581:1131-1136) demonstrated that intracerebral injections of a melanocortin agonist to DIO rats ameliorated insulin sensitivity in the periphery, decreased the size of and increased the number of adipocytes in white adipose tissue and decreased triglycerides content in the liver.

Considering the large numbers of overweight and/or insulin resistant subjects in need of treatment, intracerebral administration is an unlikely means to disperse medicaments to patients. There is a need in the art, therefore, to identify melanocortin agonists and antagonists suitable for peripheral administration to affect parameters of insulin action and energy metabolism such as insulin sensitivity, cellular characteristics of white adipose tissue, triglyceride levels and the like.

Nomenclature and Abbreviations

As used herein, an “obese subject” or mammal is characterized as having a body weight approximately 20% or greater than the normal body weight for said subject. Normal body weight may be determined by a comparison of the weight of the subject at a prior point in time, such as when insulin metabolism was normal, or by a comparison of the weight of the subject as compared to averages of other subjects of a similar age and/or condition.

As used herein, an “overweight subject” or mammal is characterized as having a body weight approximately 5% greater to approximately 20% greater than the normal body weight for said subject. Normal body weight may be determined by a comparison of the weight of the subject at a prior point in time, such as when insulin metabolism was normal, or by a comparison of the weight of the subject as compared to averages of other subjects of a similar age and/or condition.

As used herein, a “normal subject” or mammal is characterized as having a body weight up to approximately 5% greater than to approximately 5% less than the normal body weight for said subject. Normal body weight may be determined by a comparison of the weight of the subject at a prior point in time, such as when insulin metabolism was normal, or by a comparison of the weight of the subject as compared to averages of other subjects of a similar age and/or condition.

As used herein, a “lean subject” or mammal is characterized as having a body weight approximately 5% to 30% or even to 50% less than the normal body weight for said subject. Normal body weight may be determined by a comparison of the weight of the subject at a prior point in time, such as when insulin metabolism was normal, or by a comparison of the weight of the subject as compared to averages of other subjects of a similar age and/or condition.

As used herein, the terms “treat”, “treating” and “treatment” include palliative, curative and prophylactic treatment.

As used herein, “measurable” means the biologic effect is both reproducible and significantly different from the baseline variability of the assay.

As used herein, peripherial administration includes all forms of administration of a compound or a composition comprising a compound of the instant invention which excludes intracranial administration. Examples of peripheral administration include, but are not limited to, oral, parenteral (e.g., intramuscular, intraperitoneal, intravenous or subcutaneous injection, implant and the like), nasal, vaginal, rectal, sublingual or topical routes of administration, including transdermal patch applications and the like.

A “subject”, as used herein and throughout this application, refers to a mammalian or non-mammalian animal including, for example and without limitation, a human, a rat, a mouse or farm animal. Reference to a subject does not necessarily indicate the presence of a disease or disorder. The term “subject” includes, for example, a mammalian or non-mammalian animal being dosed with a melanocortin analog as part of an experiment, a mammalian or non-mammalian animal being treated to help alleviate a disease or disorder, and a mammalian or non-mammalian animal being treated prophylactically to retard or prevent the onset of a disease or disorder. Subject mammals may be human subjects of any age, such as an infant, a child, an adult or an elderly adult.

A “therapeutically acceptable amount” of a compound or composition of the invention, regardless of the formulation or route of administration, is that amount which elicits a desired biological response in a subject. The biological effect of the therapeutic amount may occur at and be measured at many levels in an organism. For example, the biological effect of the therapeutic amount may occur at and be measured at the cellular level by measuring the response at a receptor which binds melanocortin and/or a melanocortin analog, or the biological effect of the therapeutic amount may occur at and be measured at the system level, such as effecting an increase/decrease in the levels of insulin. The biological effect of the therapeutic amount may occur at and be measured at the organism level, such as the alleviation of a symptom(s) or progression of a disease or condition in a subject. A therapeutically acceptable amount of a compound or composition of the invention, regardless of the formulation or route of administration, may result in one or more biological responses in a subject. In the event that the compound or composition of the invention is subject to testing in an in vitro system, a therapeutically acceptable amount of the compound or composition may be viewed as that amount which gives a measurable response in the in vitro system of choice.

The nomenclature used to define the peptides is that typically used in the art wherein the amino group at the N-terminus appears to the left and the carboxyl group at the C-terminus appears to the right. Where the amino acid has D and L isomeric forms, it is the L form of the amino acid that is represented unless otherwise explicitly indicated.

The compounds of the invention useful for the treatment of insulin resistance, with or without weight loss, may possess one or more chiral centers and so exist in a number of stereoisomeric forms. All stereoisomers and mixtures thereof are included in the scope of the present invention. Racemic compounds may either be separated using preparative HPLC and a column with a chiral stationary phase or resolved to yield individual enantiomers utilizing methods known to those skilled in the art. In addition, chiral intermediate compounds may be resolved and used to prepare chiral compounds of the invention.

The compounds of the invention useful for the treatment of insulin resistance, with or without weight loss, may exist in one or more tautomeric forms. All tautomers and mixtures thereof are included in the scope of the present invention. For example, a claim to 2-hydroxypyridinyl would also cover its tautomeric form, α-pyridonyl.

Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. Also, all publications, patent applications, patents and other references mentioned herein are incorporated by reference in their entirety.

Symbol Meaning Abu α-aminobutyric acid Ac acyl group Acc 1-amino-1-cyclo(C₃-C₉)alkyl carboxylic acid A3c 1-amino-1-cyclopropanecarboxylic acid A4c 1-amino-1-cyclobutanecarboxylic acid A5c 1-amino-1-cyclopentanecarboxylic acid A6c 1-amino-1-cyclohexanecarboxylic acid Aha 7-aminoheptanoic acid Ahx 6-aminohexanoic acid Aib α-aminoisobutyric acid Aic 2-aminoindan-2-carboxylic acid Ala or A alanine β-Ala β-alanine Apc denotes the structure:

Apn 5-aminopentanoic acid (HN—(CH₂)₄—C(O) Arg or R arginine hArg homoarginine Asn or N asparagine Asp or D aspartic acid Bal 3-benzothienylalanine Bip 4,4′-biphenylalanine, represented by the structure

Bpa 4-benzoylphenylalanine 4-Br—Phe 4-bromo-phenylalanine Cha β-cydohexylalanine hCha homo-cyclohexylalanine Chg cydohexylglycine Cys or C cysteine hCys homocysteine Dab 2,4-diaminobutyric acid Dap 2,3-diaminopropionic acid Dip β,β-diphenylalanine Doc 8-amino-3,6-dioxaoctanoic acid with the structure of:

2-Fua β-(2-furyl)-alanine Gaba 4-aminobutyric acid Gln or Q glutamine Glu or E glutamic acid Gly or G glycine His or H histidine 3-Hyp trans-3-hydroxy-L-proline, i.e., (2S, 3S)- 3-hydroxypyrrolidine-2-carboxylic acid 4-Hyp 4-hydroxyproline, i.e., (2S, 4R)- 4-hydroxypyrrolidine-2-carboxylic acid Ile or I isoleucine Leu or L leucine hLeu homoleucine Lys or K lysine Met or M methionine β-hMet β-homomethionine 1-Nal β-(1-naphthyl)alanine: 2-Nal β-(2-naphthyl)alanine Nip nipecotic acid Nle norleucine Oic octahydroindole-2-carboxylic acid Orn ornithine 2-Pal β-(2-pyridiyl)alanine 3-Pal β-(3-pyridiyl)alanine 4-Pal β-(4-pyridiyl)alanine Pen penicillamine Pff (S)-pentafluorophenylalanine Phe or F phenylalanine hPhe homophenylalanine Pro or P proline hPro homoproline Ser or S serine Tle tert-Leucine Taz β-(4-thiazolyl)alanine 2-TN β-(2-thienyl)alanine 3-TN β-(3-thienyl)alanine Thr or T threonine Trp or W tryptophan Tyr or Y tyrosine D-(Et)Tyr has a structure of

Val or V valine Certain other abbreviations used herein are defined as follows: Boc: tert-butyloxycarbonyl Bzl: benzyl DCM: dichloromethane DIC: N, N-diisopropylcarbodiimide DIEA: diisopropylethyl amine Dmab: 4-{N-(1-(4,4-dimethy1-2,6-dioxocyclohexylidene)- 3-methylbutyl)-amino}benzyl DMAP: 4-(dimethylamino)pyridine DMF dimethylformamide DNP: 2,4-dinitrophenyl Fm: fluorenylmethyl Fmoc: fluorenylmethyloxycarbonyl For: formyl HBTU: 2-(1H-benzotriazole-1-yl)-1,1,3,3-tetramethyluronium hexafluorophosphate cHex cyclohexyl HOAT: O-(7-azabenzotriazol-1-yl)-1,1,3,3-tetramethyluronium hexafluorophosphate HOBt: 1-hydroxy-benzotriazole MBHA 4-methylbenzhydrylamine Mmt: 4-methoxytrityl NMP: N-methylpyrrolidone O-tBu oxy-tert-butyl Pbf: 2,2,4,6,7-pentamethyldihydrobenzofuran-5-sulfonyl PyBroP bromo-tris-pyrrolidino-phosphonium hexafluorophosphate tBu: tert-butyl TIS: triisopropylsilane TOS: tosyl Trt trityl TFA: trifluoro acetic acid TFFH: tetramethylfluoroforamidinium hexafluorophosphate Z: benzyloxycarbonyl

Unless otherwise indicated, with the exception of the N-terminal amino acid, all abbreviations (e.g. Ala) of amino acids in this disclosure stand for the structure of —NH—C(R)(R′)—CO—, wherein R and R′ each is, independently, hydrogen or the side chain of an amino acid (e.g., R=CH₃ and R′=H for Ala), or R and R′ may be joined to form a ring system.

For the N-terminal amino acid, the abbreviation stands for the structure of:

The designation “NH₂” in e.g., Ac-Nle-c(Cys-D-Ala-His-D-Phe-Arg-Trp-Cys)-NH₂ (SEQ ID NO:7), indicates that the C-terminus of the peptide is amidated. Ac-Nle-c(Cys-D-Ala-His-D-Phe-Arg-Trp-Cys) (SEQ ID NO:36), or alternatively Ac-Nle-c(Cys-D-Ala-His-D-Phe-Arg-Trp-Cys)-OH (SEQ ID NO:36), indicates that the C-terminus is the free acid.

“-c(Cys-Cys)-” or “-cyclo(Cys-Cys)-” denotes the structure:

“-c(Cys-Pen)-” or “-cyclo(Cys-Pen)-” denotes the structure:

“-c(Asp-Lys)-” or “-cyclo(Asp-Lys)-” denotes the structure:

Applicants have devised the following shorthand used in naming the specific embodiments and/or species:

“Hydantoin(C(O)-(A^(a)-A^(b))” denotes the structure:

wherein amino acid “A^(a)” has the structure:

and

amino acid “A^(b)” the structure:

For example, a compound represented as “c[Hydantoin(C(O)-(Cys-A^(b)))-A¹-A²-A³-A⁴-Cys]-” would have the following the structure:

whereas a compound represented as “c[Hydantoin(C(O)-(A^(b)-Cys))-A¹-A²-A³-A⁴-Cys]-” would have the structure:

For further guidance, “c[Hydantoin(C(O)-(Asp-A^(b)))-A¹-A²-A³-A⁴-Lys]-” represents the following compound:

whereas “c[Hydantoin(C(O)-(Dap-A^(b)))-A¹-A²-A³-A⁴-Asp]-” has the following formula:

“Acyl” refers to R″—C(O)—, where R″ is H, alkyl, substituted alkyl, heteroalkyl, substituted heteroalkyl, alkenyl, substituted alkenyl, aryl, alkylaryl, or substituted alklyaryl, and is indicated in the general formula of a particular embodiment as “Ac”.

“Alkyl” refers to a hydrocarbon group containing one or more carbon atoms, where multiple carbon atoms if present are joined by single bonds. The alkyl hydrocarbon group may be straight-chain or contain one or more branches or cyclic groups.

“Hydroxyalkyl” refers to an alkyl group wherein one or more hydrogen atoms of the hydrocarbon group are substituted with one or more hydroxy radicals, such as hydroxymethyl, hydroxyethyl, hydroxypropyl, hydroxybutyl, hydroxypentyl, hydroxyhexyl and the like.

“Substituted alkyl” refers to an alkyl wherein one or more hydrogen atoms of the hydrocarbon group are replaced with one or more substituents selected from the group consisting of halogen, (i.e., fluorine, chlorine, bromine, and iodine), —OH, —CN, —SH, —NH₂, —NHCH₃, —NO₂, and —C₁₋₂₀ alkyl, wherein said —C₁₋₂₀ alkyl optionally may be substituted with one or more substituents selected, independently for each occurrence, from the group consisting of halogens, —CF₃, —OCH₃, —OCF₃, and —(CH₂)₀₋₂₀—COOH. In different embodiments 1, 2, 3 or 4 substituents are present. The presence of —(CH₂)₀₋₂₀—COOH results in the production of an alkyl acid. Non-limiting examples of alkyl acids containing, or consisting of, —(CH₂)₀₋₂₀—COOH include 2-norbornane acetic acid, tert-butyric acid, 3-cyclopentyl propionic acid, and the like.

The term “halo” encompasses fluoro, chloro, bromo and iodo.

“Heteroalkyl” refers to an alkyl wherein one of more of the carbon atoms in the hydrocarbon group is replaced with one or more of the following groups: amino, amido, —O—, —S— or carbonyl. In different embodiments 1 or 2 heteroatoms are present.

“Substituted heteroalkyl” refers to a heteroalkyl wherein one or more hydrogen atoms of the hydrocarbon group are replaced with one or more substituents selected from the group consisting of halogen, (i.e., fluorine, chlorine, bromine, and iodine), —OH, —CN, —SH, —NH₂, —NHCH₃, —NO₂, and —C₁₋₂₀ alkyl, wherein said —C₁₋₂₀ alkyl optionally may be substituted with one or more substituents selected, independently for each occurrence, from the group consisting of halogens, —CF₃, —OCH₃, —OCF₃, and —(CH₂)₀₋₂₀—COOH. In different embodiments 1, 2, 3 or 4 substituents are present.

“Alkenyl” refers to a hydrocarbon group made up of two or more carbons where one or more carbon-carbon double bonds are present. The alkenyl hydrocarbon group may be straight-chain or contain one or more branches or cyclic groups.

“Substituted alkenyl” refers to an alkenyl wherein one or more hydrogens are replaced with one or more substituents selected from the group consisting of halogen (i.e., fluorine, chlorine, bromine, and iodine), —OH, —CN, —SH, —NH₂, —NHCH₃, —NO₂, and —C₁₋₂₀ alkyl, wherein said —C₁₋₂₀ alkyl optionally may be substituted with one or more substituents selected, independently for each occurrence, from the group consisting of halogens, —CF₃, —OCH₃, —OCF₃, and —(CH₂)₀₋₂₀—COOH. In different embodiments 1, 2, 3 or 4 substituents are present.

“Aryl” refers to an optionally substituted aromatic group with at least one ring having a conjugated pi-electron system, containing up to three conjugated or fused ring systems. Aryl includes carbocylic aryl, heterocyclic aryl and biaryl groups. Preferably, the aryl is a 5- or 6-membered ring. Preferred atoms for a heterocyclic aryl are one or more sulfur, oxygen, and/or nitrogen. Non-limiting examples of aryl include phenyl, 1-naphthyl, 2-naphthyl, indole, quinoline, 2-imidazole, 9-anthracene, and the like. Aryl substituents are selected from the group consisting of —C₁₋₂₀ alkyl, —C₁₋₂₀ alkoxy, halogen (i.e., fluorine, chlorine, bromine, and iodine), —OH, —CN, —SH, —NH₂, —NO₂, —C₁₋₂₀ alkyl substituted with halogens, —CF₃, —OCF₃, and —(CH₂)₀₋₂₀—COOH. In different embodiments the aryl contains 0, 1, 2, 3, or 4 substituents.

“Alkylaryl” refers to an “alkyl” joined to an “aryl”.

The term “(C₁-C₁₂)hydrocarbon moiety” encompasses alkyl, alkenyl and alkynyl and in the case of alkenyl and alkynyl there is C₂-C₁₂.

For the avoidance of doubt, unless otherwise indicated, the term substituted means substituted by one or more defined groups. In the case where groups may be selected from a number of alternative groups, the selected groups may be the same or different. For the avoidance of doubt, the term independently means that where more than one substituent is selected from a number of possible substituents, those substituents may be the same or different.

The pharmaceutically acceptable salts of the compounds of the invention which contain a basic centre are, for example, non-toxic acid addition salts formed with inorganic acids such as hydrochloric, hydrobromic, hydroiodic, sulfuric and phosphoric acid, with carboxylic acids or with organo-sulfonic acids. Examples include the HCl, HBr, HI, sulfate or bisulfate, nitrate, phosphate or hydrogen phosphate, acetate, benzoate, succinate, saccharate, fumarate, maleate, lactate, citrate, tartrate, gluconate, camsylate, methanesulfonate, ethanesulfonate, benzenesulfonate, p-toluenesulfonate and pamoate salts. Compounds of the invention can also provide pharmaceutically acceptable metal salts, in particular non-toxic alkali and alkaline earth metal salts, with bases. Examples include the sodium, potassium, aluminum, calcium, magnesium, zinc and diethanolamine salts (Berge, S. M. et al., J. Pharm. Sci., 66:1-19 (1977); Gould, P. L., Int'l J. Pharmaceutics, 33:201-17 (1986); and Bighley, L. D. et al., Encyclo. Pharma. Tech., Marcel Dekker Inc, New York, 13:453-97 (1996).

The pharmaceutically acceptable solvates of the compounds of the invention include the hydrates thereof. Also included within the scope of the invention and various salts of the invention are polymorphs thereof. Hereinafter, compounds their pharmaceutically acceptable salts, their solvates or polymorphs, defined in any aspect of the invention (except intermediate compounds in chemical processes) are referred to as “compounds of the invention”.

In Vitro Studies

Compounds of the present invention can be and were tested for activity as ligands of one or more of the melanocortin receptors according to the following procedures. One skilled in the art would know that procedures similar to those described herein may be used to assay the binding activities of the compounds of the invention to melanocortin receptor molecules.

Radioligand Binding Assays

Cellular membranes used for the in vitro receptor binding assays were obtained from transgenic CHO-K1 cells stably expressing hMC-R receptor subtypes 1, 3, 4 or 5. The CHO-K1 cells expressing the desired hMC-R receptor type were sonicated (Branson® setting 7, approximately 30 sec) in ice-cold 50 mM Tris-HCl at pH 7.4 and then centrifuged at 39,000 g for 10 minutes at approximately 4° C. The pellets were resuspended in the same buffer and centrifuged at 50,000 g for 10 minutes at approximately 4° C. The washed pellets containing the cellular membranes were stored at approximately −80° C.

Competitive inhibition of [¹²⁵I](Tyr²)-(Nle⁴-D-Phe⁷)α-MSH ([¹²⁵I]-NDP-α-MSH, Amersham Biosciences®) binding was carried out in polypropylene 96 well plates. Cell membranes (1-10 μg protein/well) prepared as described above were incubated in 50 mM Tris-HCl at pH 7.4 containing 0.2% bovine serum albumin (BSA), 5 mM MgCl₂, 1 mM CaCl₂ and 0.1 mg/mL bacitracin, with increasing concentrations of the test compound and 0.1-0.3 nM [¹²⁵I]-NDP-α-MSH for approximately 90-120 minutes at approximately 37° C. Bound [¹²⁵I]-NDP-α-MSH ligand was separated from free [¹²⁵I]-NDP-α-MSH by filtration through GF/C glass fiber filter plates (Unifilter®; Packard) presoaked with 0.1% (w/v) polyethylenimine (PEI), using a Packard Filtermate® harvester. Filters were washed three times with 50 mM Tris-HCl at pH 7.4 at a temperature of approximately 0-4° C. and then assayed for radioactivity using a Packard Topcount® scintillation counter. Binding data were analyzed by computer-assisted non-linear regression analysis (XL fit; IDBS). A selection of the preferred embodiments was tested using the above-discussed assay and the binding constants (Ki in nM) are reported in Tables 5, 6, 7 and 8.

TABLE 5 Radioligand Binding Assay Data for Selected Compounds Ki Ki Ki Ki Ki hMC1-R/ SEQ ID Compound hMC1-R hMC3-R hMC4-R hMC5-R MC4-R NO: Ac-Arg-c(Cys-D-Ala-His-D- 3.87 10.1 2.09 430 1.9 SEQ ID Phe-Arg-Trp-Cys)-NH₂ NO: 50 Ac-D-Arg-c(Cys-D-Ala-His- 4.01 12.1 1.76 352 2.3 SEQ ID D-Phe-Arg-Trp-Cys)-NH₂ NO: 50 Ac-D-Arg-c(Cys-D-Ala-His- 8.29 13.3 2.78 816 3.0 SEQ ID D-Phe-Arg-Trp-Pen)-NH₂ NO: 51 Ac-D-Arg-c(Cys-His-D-Phe- 3.93 172 11.0 538 0.36 SEQ ID Arg-Trp-Gaba-Pen)-NH₂ NO: 52 Ac-Arg-c(Cys-His-D-Phe- 1.81 20.5 4.57 502 0.4 SEQ ID Arg-Trp-Gaba-Pen)-NH₂ NO: 52 Ac-Arg-c(Cys-D-Ala-His-D- 9.67 22.0 4.2 1900 2.3 SEQ ID Phe-Arg-Trp-Pen)-NH₂ NO: 51 Ac-D-Arg-c(Asp-His-D- 0.79 45.5 1.21 493 0.6 SEQ ID Phe-Arg-Trp-Ala-Lys)-NH₂ NO: 53 Ac-Arg-c(Asp-His-D-Phe- 0.68 20.7 1.01 783 0.7 SEQ ID Arg-Trp-Ala-Lys)-NH₂ NO: 53 Ac-Nle-c(Cys-D-Ala-His-D- 114 63.9 3.07 1657 37.1 SEQ ID 2-Nal-Arg-1-Nal-Cys)-NH₂ NO: 16 Ac-Nle-c(Cys-D-Ala-His-D- 11 26 7.6 1800 1.4 SEQ ID Phe-Arg-Trp-Cys)-NH₂ NO: 7 D-Phe-c(Cys-His-D-(Et)Tyr- 0.05 9.3 1.1 2.9 0.0 SEQ ID Arg-Trp-β-Ala-D-Cys)-Thr- NO: 24 NH₂ Nle-c(Cys-His-D-Phe-Arg- 0.07 4.1 0.85 8.8 0.1 SEQ ID Trp-Apn-Cys)-NH₂ NO: 27 Ac-Nle-c(Cys-His-D-Phe- 0.12 10 0.43 0.42 0.3 SEQ ID Arg-Trp-Gaba-Pen)-NH₂ NO: 32 Nle-c(Cys-His-D-Phe-Arg- 0.05 1.3 0.47 0.2 0.1 SEQ ID Trp-Gaba-Cys)-NH₂ NO: 34 Ac-Nle-c(Asp-His-D-Phe- 0.0996 9318 0.617 10.9 0.16 SEQ ID Arg-Trp-β-Ala-Lys)-NH₂ NO: 1 Ac-Nle-c(Cys-His-D-Phe- .0132 16.1 1.23 0.359 0.11 SEQ ID Arg-Trp-Ahx-Cys)-NH₂ NO: 2 D-Phe-c(Cys-His-D-Phe- 0.207 43.2 2.58 344 0.08 SEQ ID Arg-Trp-β-Ala-D-Cys)-Thr- NO: 3 NH₂ D-Phe-c(Cys-His-D-Phe- 0.420 106 4.75 1260 0.09 SEQ ID Arg-Trp-Gaba-D-Cys)-Thr- NO: 3 NH₂ Ac-Nle-c(Cys-His-D-Phe- 0.0951 9.33 0.894 13.4 0.11 SEQ ID Arg-Trp-Apn-Cys)-NH₂ NO: 2 Ac-Nle-c(Asp-His-D-Phe- 0.999 300 11.1 431 0.09 SEQ ID Arg-Trp-Apn-Lys)-NH₂ NO: 4 Ac-Cha-c(Asp-His-D-Phe- 0.106 11.8 1.49 110 0.07 SEQ ID Arg-Trp-Gaba-Lys)-NH₂ NO: 6 Ac-Nle-c(Asp-His-D-Phe- 0.0506 9.89 1.04 16.3 0.05 SEQ ID Arg-Trp-Gaba-Lys)-NH₂ NO: 6 Ac-Chg-c(Asp-His-D-Phe- 0.884 223 22.5 609 0.04 SEQ ID Arg-Trp-Gaba-Lys)-NH₂ NO: 11 Ac-hCha-c(Asp-His-D-Phe- 0.721 93.5 56.0 747 0.01 SEQ ID Arg-Trp-Gaba-Lys)-NH₂ NO: 11 Ac-D-Chg-c(Asp-His-D- 0.227 14.5 2.99 164 0.08 SEQ ID Phe-Arg-Trp-Gaba-Lys)- NO: 11 NH₂ Ac-hPhe-c(Asp-His-D-Phe- 0.277 25.2 3.37 203 0.08 SEQ ID Arg-Trp-Gaba-Lys)-NH₂ NO: 11 Ac-Nle-c(Cys-His-D-Phe- 0.323 14.1 1.96 24.0 0.16 SEQ ID Arg-D-Trp-β-Ala-Cys)-NH₂ NO: 15 Ac-Nle-c(Pen-D-Ala-His-D- 34.1 118 17.0 5560 2.01 SEQ ID Phe-Arg-Trp-Cys)-NH₂ NO: 21 Ac-Nle-c(Cys-D-Ala-His-D- 29.1 22.8 3.84 2550 7.58 SEQ ID Phe-Arg-Trp-Pen)-NH₂ NO: 22 D-Phe-c(Cys-His-D-Phe- 0.442 123 10.3 521 0.04 SEQ ID hArg-Trp-β-Ala-D-Cys)- NO: 23 Thr-NH₂ D-Phe-c(Cys-His-D-Phe- 5.80 3370 583 1130 0.01 SEQ ID Arg-Bip-β-Ala-D-Cys)-Thr- NO: 25 NH₂ D-Phe-c(Cys-His-D-(Et)Tyr- 0.0567 31.4 14.7 9.27 0 SEQ ID hArg-Trp-β-Ala-D-Cys)- NO: 24 Thr-NH₂ D-Phe-c(Cys-His-D-Phe- 1.68 1260 172 1220 0.01 SEQ ID hArg-Bip-β-Ala-D-Cys)- NO: 26 Thr-NH₂ D-Phe-c(Cys-His-D-(Et)Tyr- 0.128 85.6 36.9 38.0 0 SEQ ID hArg-Bip-β-Ala-D-Cys)- NO: 26 Thr-NH₂ Ac-Nle-c(Cys-D-Ala-His-D- 0.352 149 3.01 339 0.12 SEQ ID Phe-Arg-Trp-Gly-Cys)-NH₂ NO: 54 Ac-Nle-c(Cys-D-Ala-His-D- 3.93 876 48.0 4940 0.08 SEQ ID Phe-Arg-Trp-D-Ala-Cys)- NO: 54 NH₂ Ac-Nle-c(Cys-D-Ala-His-D- 0.995 287 4.80 766 0.21 SEQ ID Phe-Arg-Trp-β-Ala-Cys)- NO: 54 NH₂ Ac-Nle-c(Cys-D-Ala-His-D- 0.848 184 3.76 956 0.23 SEQ ID Phe-Arg-Trp-Gaba-Cys)- NO: 54 NH₂ Ac-Nle-c(Cys-D-Ala-His-D- 1.10 228 7.58 859 0.15 SEQ ID Phe-Arg-Trp-Apn-Cys)- NO: 54 NH₂ Ac-Nle-c(Asp-D-Ala-His-D- 0.659 98.9 2.55 4.19 0.26 SEQ ID Phe-Arg-Trp-Lys)-NH₂ NO: 28 Ac-Nle-c(Asp-D-Ala-His-D- 4.12 445 50.6 4300 0.08 SEQ ID Phe-Arg-Bal-Lys)-NH₂ NO: 28 Ac-c(Cys-Glu-His-D-Phe- 111 1710 47.7 694 2.33 SEQ ID Arg-Trp-Ala-Cys)-NH₂ NO: 55 Ac-c(Cys-Glu-His-D-Phe- 262 2500 96.4 1460 2.72 SEQ ID Arg-2-Nal-Ala-Cys)-NH₂ NO: 55 Ac-c(Cys-D-Ala-His-D-Phe- 199 5990 96.7 >10000 2.06 SEQ ID Arg-Trp-Ala-Cys)-NH₂ NO: 56 Ac-c(Cys-D-Ala-His-D-Phe- 132 4560 40.7 8810 3.24 SEQ ID Arg-2-Nal-Ala-Cys)-NH₂ NO: 56 Ac-Nle-c(Cys-D-Ala-His-D- 9.12 1130 22.1 2860 0.41 SEQ ID Phe-Arg-Trp-Ala-Cys)-NH₂ NO: 57 Ac-Nle-c(Cys-D-Ala-His-D- 1.00 227 5.55 496 0.18 SEQ ID Phe-Arg-Trp-β-Ala-Cys)- NO: 57 NH₂ Ac-Nle-c(Cys-D-Ala-His-D- 0.536 169 3.12 358 0.17 SEQ ID Phe-Arg-Trp-Gaba-Cys)- NO: 57 NH₂ Ac-Nle-c(Cys-D-Ala-His-D- 32.1 330 17.4 165 1.84 SEQ ID Phe-Arg-Trp-Pen)-OH NO: 29 Ac-Nle-c(Cys-D-Abu-His- 10.6 41.1 7.69 54.9 1.38 SEQ ID D-Phe-Arg-Trp-Cys)-NH₂ NO: 30 Ac-Nle-c(Cys-D-Val-His-D- 13.0 104 10.1 40 1.29 SEQ ID Phe-Arg-Trp-Cys)-NH₂ NO: 30 Ac-Nle-c(Cys-D-Ile-His-D- 4.28 38.5 9.0 12.5 0.48 SEQ ID Phe-Arg-Trp-Cys)-NH₂ NO: 30 Ac-Nle-c(Cys-D-Leu-His-D- 1.60 6.82 4.13 5.57 0.39 SEQ ID Phe-Arg-Trp-Cys)-NH₂ NO: 30 Ac-Nle-c(Cys-D-Tle-His-D- 12.0 85.8 11.2 40 1.07 SEQ ID Phe-Arg-Trp-Cys)-NH₂ NO: 30 Ac-Nle-c(Cys-D-Cha-His-D- 0.353 2.08 1.41 0.857 0.25 SEQ ID Phe-Arg-Trp-Cys)-NH₂ NO: 30 Ac-Nle-c(Pen-His-D-Phe- 0.537 86.1 5.89 2.56 0.09 SEQ ID Arg-Trp-Gaba-Cys)-NH₂ NO: 31 Ac-Nle-c(Pen-His-D-Phe- 0.744 178 3.51 2.69 0.21 SEQ ID Arg-Trp-Gaba-Pen)-NH₂ NO: 32 Ac-Leu-c(Cys-His-D-Phe- 0.216 17.4 0.995 0.486 0.22 SEQ ID Arg-Trp-Gaba-Cys)-NH₂ NO: 33 Ac-Cha-c(Cys-His-D-Phe- 0.107 9.11 0.884 0.354 0.12 SEQ ID Arg-Trp-Gaba-Cys)-NH₂ NO: 33 Ac-Ile-c(Cys-His-D-Phe- 0.148 13.9 1.06 0.423 0.14 SEQ ID Arg-Trp-Gaba-Cys)-NH₂ NO: 33 Ac-Phe-c(Cys-His-D-Phe- 0.254 18.5 2.13 0.714 0.12 SEQ ID Arg-Trp-Gaba-Cys)-NH₂ NO: 33 Ac-Val-c(Cys-His-D-Phe- 0.256 29.9 1.98 0.864 0.13 SEQ ID Arg-Trp-Gaba-Cys)-NH₂ NO: 33 Ac-2-Nal-c(Cys-His-D-Phe- 0.560 39.2 2.94 2.73 0.19 SEQ ID Arg-Trp-Gaba-Cys)-NH₂ NO: 33 Phe-c(Cys-His-D-Phe-Arg- 0.186 15.2 4.93 0.537 0.04 SEQ ID Trp-Gaba-Cys)-NH₂ NO: 34 Ac-Nle-c(Cys-3-Pal-D-Phe- 21.1 151 10.4 92.6 2.03 SEQ ID Arg-Trp-Gaba-Cys)-NH₂ NO: 35 Ac-Nle-c(Cys-D-Ala-His-D- 30.7 152 15.6 114 1.97 SEQ ID Phe-Arg-Trp-Cys)-OH NO: 36 Ac-Nle-c(Cys-His-Phe-Arg- 5.20 150 138 20.3 0.04 SEQ ID D-Trp-Gaba-Cys)-NH₂ NO: 37 Ac-Nle-c(Asp-D-Ala-His-D- 4.89 290 21.3 11.1 0.23 SEQ ID Phe-Arg-Bal-Ala-Lys)-NH₂ NO: 58 Ac-Nle-c(Cys-D-Ala-His-D- 25.5 3.82 7.61 102 3.35 SEQ ID 2-Nal-Arg-Trp-Cys)-NH₂ NO: 16 Ac-Nle-c(Cys-D-Ala-His-D- 32.5 5.85 2.53 94.6 12.85 SEQ ID 2-Nal-Arg-2-Nal-Cys)-NH₂ NO: 16 Ac-Nle-c(Cys-D-Ala-His-D- 22.2 12.7 16.6 125 1.34 SEQ ID 2-Nal-Arg-Bal-Cys)-NH₂ NO: 20 Ac-Nle-c(Asp-His-D-2-Nal- 1.17 1.56 0.277 3.24 4.22 SEQ ID Arg-Trp-Ala-Lys)-NH₂ NO: 38 Ac-Nle-c(Asp-His-D-2-Nal- 0.648 2.78 0.329 1.4 1.97 SEQ ID Arg-Trp-β-Ala-Lys)-NH₂ NO: 38 Ac-Nle-c(Cys-His-D-2-Nal- 0.393 1.86 0.375 1.11 1.05 SEQ ID Arg-Trp-Gaba-Cys)-NH₂ NO: 39 Ac-Nle-c(Cys-His-D-2-Nal- 0.333 2.91 0.998 0.366 0.33 SEQ ID Arg-Trp-Ahx-Cys)-NH₂ NO: 39 Ac-hPhe-c(Asp-His-D-2- 0.461 2.45 0.931 1.37 0.50 SEQ ID Nal-Arg-Trp-Gaba-Lys)- NO: 40 NH₂ Ac-Cha-c(Asp-His-D-2-Nal- 0.576 3.98 2.82 3.91 0.20 SEQ ID Arg-Trp-Gaba-Lys)-NH₂ NO: 40 Ac-Arg-c(Cys-D-Ala-His-D- 17.9 1.68 0.256 23.4 69.9 SEQ ID 2-Nal-Arg-Trp-Cys)-NH₂ NO: 49

TABLE 6 Radioligand Binding Assay Data for Selected Compounds Ki Ki Ki Ki Compound hMC1-R hMC3-R hMC4-R hMC5-R Ac-c(Cys-Glu-His-D-2-Nal-Arg-Trp-Ala- 49.9 9.00 0.569 218 Cys)-Pro-Pro-Lys-Asp-NH₂ (SEQ ID NO: 269) Tyr-Gly-Arg-Lys-Lys-Arg-Arg-Gln-Arg-Arg- 11.9 38.1 5.70 11.8 Arg-Nle-c(Asp-His-D-2-Nal-Arg-Trp-Lys)- NH₂ (SEQ ID NO: 60) Tyr-Gly-Arg-Lys-Lys-Arg-Arg-Gln-Arg-Arg- 3.46 16.6 6.65 4.88 Arg-Doc-Nle-c(Asp-His-D-2-Nal-Arg-Trp- Lys)-NH₂ (SEQ ID NO: 61) Nle-c(Asp-His-D-2-Nal-Arg-Trp-Lys)-β-Ala- 0.614 5.09 2.31 3.23 Tyr-Gly-Arg-Lys-Lys-Arg-Arg-Gln-Arg-Arg- Arg-NH₂ (SEQ ID NO: 62) Ac-Nle-c(Asp-His-D-2-Nal-Arg-Trp-Lys)-β- 1.56 14.1 5.17 7.12 Ala-Tyr-Gly-Arg-Lys-Lys-Arg-Arg-Gln-Arg- Arg-Arg-NH₂ (SEQ ID NO: 62) H-Nle-c(Asp-His-D-2-Nal-Arg-Trp-Lys)-Doc- 1.10 1.58 6.00 0.629 Doc-Tyr-Gly-Arg-Lys-Lys-Arg-Arg-Gln-Arg- Arg-Arg-NH₂ (SEQ ID NO: 63) Ac-Nle-c(Asp-His-D-2-Nal-Arg-Trp-Lys)- 0.0868 0.751 0.0944 0.147 Pro-Pro-Lys-Asp-Tyr-Gly-Arg-Lys-Lys-Arg- Arg-Gln-Arg-Arg-Arg-NH₂ (SEQ ID NO: 64) Ac-c(Cys-Glu-His-D-2-Nal-Arg-Trp-Gly- 1.66 4.80 0.250 9.62 Cys)-Pro-Pro-Lys-Asp-Tyr-Gly-Arg-Lys-Lys- Arg-Arg-Gln-Arg-Arg-Arg-NH₂ (SEQ ID NO: 65) Ac-Nle-c(Asp-His-D-2-Nal-Arg-Trp-Lys)-β- 0.0452 0.298 0.169 0.386 Ala-β-Ala-Tyr-Gly-Arg-Lys-Lys-Arg-Arg- Gln-Arg-Arg-Arg-NH₂ (SEQ ID NO: 66) Ac-Nle-c(Asp-His-D-2-Nal-Arg-Trp-Lys)- 0.0808 0.396 0.0747 0.311 Pro-Pro-Lys-Asp-Doc-Tyr-Gly-Arg-Lys-Lys- Arg-Arg-Gln-Arg-Arg-Arg-NH₂ (SEQ ID NO: 67) Ac-c(Cys-Glu-His-D-2-Nal-Arg-Trp-Gly- 4.41 4.23 0.455 12.9 Cys)-Pro-Pro-Lys-Asp-Doc-Tyr-Gly-Arg-Lys- Lys-Arg-Arg-Gln-Arg-Arg-Arg-NH₂ (SEQ ID NO: 68) Ac-c(Cys-Glu-His-D-2-Nal-Arg-Trp-Ala- 1.25 0.661 0.292 5.94 Cys)-Pro-Pro-Lys-Asp-β-Ala-Tyr-Gly-Arg- Lys-Lys-Arg-Arg-Gln-Arg-Arg-Arg-NH₂ (SEQ ID NO: 71) Ac-c(Cys-Glu-His-D-2-Nal-Arg-Trp-Ala- 1.89 0.546 0.166 6.06 Cys)-Pro-Pro-Lys-Asp-Doc-Tyr-Gly-Arg-Lys- Lys-Arg-Arg-Gln-Arg-Arg-Arg-NH₂ (SEQ ID NO: 71) Ac-c(Cys-Glu-His-D-2-Nal-Arg-2-Nal-Ala- 87.8 9.08 1.20 359 Cys)-Pro-Pro-Lys-Asp-NH₂ (SEQ ID NO: 269) Ac-c(Cys-Glu-His-D-2-Nal-Arg-1-Nal-Ala- 124 17.8 1.11 348 Cys)-Pro-Pro-Lys-Asp-NH₂ (SEQ ID NO: 269) Ac-c(Cys-Glu-His-D-2-Nal-Arg-Bal-Ala-Cys)- 163 23.0 0.586 844 Pro-Pro-Lys-Asp-NH₂ (SEQ ID NO: 269) Ac-Nle-c(Asp-His-D-2-Nal-Arg-Trp-Lys)- 0.144 0.352 0.0845 0.415 Doc-Doc-Tyr-Gly-Arg-Lys-Lys-Arg-Arg-Gln- Arg-Arg-Arg-NH₂ (SEQ ID NO: 701) Ac-c(Cys-Glu-His-D-2-Nal-Arg-2-Nal-Ala- 1.74 0.590 0.170 4.38 Cys)-Pro-Pro-Lys-Asp-β-Ala-Tyr-Gly-Arg- Lys-Lys-Arg-Arg-Gln-Arg-Arg-Arg-NH₂ (SEQ ID NO: 71) Ac-c(Cys-Glu-His-D-2-Nal-Arg-Bal-Ala-Cys)- 3.86 4.97 0.192 38.3 Pro-Pro-Lys-Asp-β-Ala-Arg-Arg-Arg-Arg- Arg-Gln-Arg-Arg-Arg-NH₂ (SEQ ID NO: 83) Ac-c(Cys-Glu-His-D-2-Nal-Arg-Bal-Ala-Cys)- 12.8 15.9 0.950 165 Pro-Pro-Lys-Asp-β-Ala-Gly-Arg-Arg-Arg- Arg-Arg-Gln-Arg-Arg-Arg-NH₂ (SEQ ID NO: 73) Ac-c(Cys-Glu-His-D-2-Nal-Arg-Bal-Ala-Cys)- 3.07 4.05 0.498 31.1 Pro-Pro-Lys-Asp-β-Ala-Tyr-Gly-Arg-Arg- Arg-Arg-Arg-Gln-Arg-Arg-Arg-NH₂ (SEQ ID NO: 74) Ac-c(Cys-Glu-His-D-2-Nal-Arg-Trp-Ala- 0.792 0.570 0.162 4.18 Cys)-Pro-Pro-Lys-Asp-βAla-Tyr-Gly-Arg- Lys-Lys-Arg-Gln-Arg-Arg-Arg-Arg-NH₂ (SEQ ID NO: 75) Ac-c(Cys-Glu-His-D-2-Nal-Arg-Trp-Ala- 0.726 0.474 0.209 5.12 Cys)-Pro-Pro-Lys-Asp-β-Ala-Tyr-Gly-Arg- Lys-Lys-Gln-Arg-Arg-Arg-Arg-Arg-NH₂ (SEQ ID NO: 76) Ac-c(Cys-Glu-His-D-2-Nal-Arg-Trp-Ala- 0.857 0.580 0.209 4.42 Cys)-Pro-Pro-Lys-Asp-β-Ala-Tyr-Gly-Arg- Lys-Gln-Lys-Arg-Arg-Arg-Arg-Arg-NH₂ (SEQ ID NO: 77) Ac-c(Cys-Glu-His-D-2-Nal-Arg-Trp-Ala- 0.813 0.675 0.269 4.20 Cys)-Pro-Pro-Lys-Asp-β-Ala-Tyr-Gly-Arg- Lys-Lys-Arg-Arg-Arg-Arg-Gln-Arg-NH₂ (SEQ ID NO: 78) Ac-c(Cys-Glu-His-D-2-Nal-Arg-Bal-Ala-Cys)- 7.84 10.2 0.783 91.8 Pro-Pro-Lys-Asp-β-Ala-Tyr-Aib-Arg-Lys- Lys-Arg-Arg-Gln-Arg-Arg-Arg-NH₂ (SEQ ID NO: 79) Ac-c(Cys-Glu-His-D-2-Nal-Arg-1-Nal-Ala- 2.93 9.07 0.293 59.0 Cys)-Pro-Pro-Arg-Asp-β-Ala-Arg-Arg-Arg- Arg-Arg-Gln-Arg-Arg-Arg-NH₂ (SEQ ID NO: 80) Ac-c(Cys-Glu-His-D-2-Nal-Arg-1-Nal-Ala- 2.42 6.56 0.238 41.7 Cys)-Pro-Pro-Lys-Asp-β-Ala-Arg-Arg-Arg- Arg-Arg-Gln-Arg-Arg-Arg-NH₂ (SEQ ID NO: 80) Ac-c(Cys-Glu-His-D-2-Nal-Arg-1-Nal-Ala- 6.66 19.3 0.819 88.8 Cys)-Pro-Pro-Lys-Asp-β-Ala-Arg-Arg-Arg- Arg-Arg-Arg-Gln-Arg-Arg-Arg-NH₂ (SEQ ID NO: 81) Ac-c(Cys-Glu-His-D-2-Nal-Arg-2-Nal-Ala- 2.63 2.09 0.0737 11.6 Cys)-Pro-Pro-Arg-Asp-β-Ala-Arg-Arg-Arg- Arg-Arg-Gln-Arg-Arg-Arg-NH₂ (SEQ ID NO: 82) Ac-c(Cys-Glu-His-D-2-Nal-Arg-2-Nal-Ala- 2.48 1.21 0.209 9.17 Cys)-Pro-Pro-Lys-Asp-β-Ala-Arg-Arg-Arg- Arg-Arg-Gln-Arg-Arg-Arg-NH₂ (SEQ ID NO: 82) Ac-c(Cys-Glu-His-D-2-Nal-Arg-2-Nal-Ala- 3.65 2.26 0.261 12.1 Cys)-Pro-Pro-Lys-Asp-β-Ala-Arg-Arg-Arg- Arg-Arg-Arg-Gln-Arg-Arg-Arg-NH₂ (SEQ ID NO: 81) Ac-c(Cys-Glu-His-D-2-Nal-Arg-Bal-Ala-Cys)- 7.32 11.0 0.659 78.0 Pro-Pro-Arg-Asp-β-Ala-Arg-Arg-Arg-Arg- Arg-Arg-Gln-Arg-Arg-Arg-NH₂(SEQ ID NO: 83) Ac-c(Cys-Glu-His-D-2-Nal-Arg-Bal-Ala-Cys)- 4.11 7.26 0.302 48.3 Pro-Pro-Arg-Asp-β-Ala-Arg-Arg-Arg-Arg- Arg-Gln-Arg-Arg-Arg-NH₂ (SEQ ID NO: 84) Ac-c(Cys-Glu-His-D-2-Nal-Arg-Bal-Ala-Cys)- 6.77 14.3 0.781 84.0 Pro-Pro-Lys-Asp-β-Ala-Arg-Arg-Arg-Arg- Arg-Arg-Gln-Arg-Arg-Arg-NH₂(SEQ ID NO: 283) Ac-c(Cys-Glu-His-D-2-Nal-Arg-Trp-Ala- 3.04 3.22 0.230 3.85 Cys)-Pro-Pro-Lys-Asp-β-Ala-Tyr-Gly-Arg- Lys-Lys-Arg-Arg-Arg-Gln-Arg-Arg-NH₂ (SEQ ID NO: 2685) Ac-c(Cys-Glu-His-D-2-Nal-Arg-Trp-Ala- 3.24 2.66 0.208 5.96 Cys)-Pro-Pro-Lys-Asp-β-Ala-Tyr-Gly-Arg- Gln-Lys-Lys-Arg-Arg-Arg-Arg-Arg-NH₂ (SEQ ID NO: 86) Ac-c(Cys-Glu-His-D-2-Nal-Arg-Trp-Ala- 1.58 1.43 0.275 2.97 Cys)-Pro-Pro-Lys-Asp-β-Ala-Tyr-Gly-Arg- Lys-Lys-Arg-Arg-Arg-Arg-Arg-Gln-NH₂ (SEQ ID NO: 87) Ac-c(Cys-Glu-His-D-2-Nal-Arg-1-Nal-Ala- 4.59 6.28 0.588 22.6 Cys)-Pro-Pro-Lys-Asp-β-Ala-Tyr-Gly-Arg- Lys-Lys-Arg-Arg-Gln-Arg-Arg-Arg-NH₂ (SEQ ID NO: 71) Ac-c(Cys-Glu-His-D-2-Nal-Arg-Bal-Ala-Cys)- 6.46 5.22 0.380 15.3 Pro-Pro-Lys-Asp-β-Ala-Tyr-Gly-Arg-Lys- Lys-Arg-Arg-Gln-Arg-Arg-Arg-NH₂ (SEQ ID NO: 71) Ac-c(Cys-Glu-His-D-2-Nal-Arg-1-Nal-Ala- 4.62 5.68 0.505 45.3 Cys)-Pro-Pro-Lys-Asp-β-Ala-Arg-Arg-Lys- Arg-Arg-Gln-Arg-Arg-Arg-NH₂ (SEQ ID NO: 88) Ac-c(Cys-Glu-His-D-2-Nal-Arg-1-Nal-Ala- 2.12 3.99 0.352 27.5 Cys)-Pro-Pro-Lys-Asp-β-Ala-Arg-Lys-Arg- Arg-Arg-Gln-Arg-Arg-Arg-NH₂ (SEQ ID NO: 89) Ac-c(Cys-Glu-His-D-2-Nal-Arg-2-Nal-Ala- 3.41 0.975 0.549 11.3 Cys)-Pro-Pro-Lys-Asp-β-Ala-Arg-Arg-Lys- Arg-Arg-Gln-Arg-Arg-Arg-NH₂ (SEQ ID NO: 88) Ac-c(Cys-Glu-His-D-2-Nal-Arg-2-Nal-Ala- 4.18 1.12 0.223 15.3 Cys)-Pro-Pro-Lys-Asp-β-Ala-Tyr-Gly-Arg- Arg-Lys-Arg-Arg-Gln-Arg-Arg-Arg-NH₂ (SEQ ID NO: 90) Ac-c(Cys-Glu-His-D-2-Nal-Arg-2-Nal-Ala- 2.71 0.732 0.202 5.53 Cys)-Pro-Pro-Lys-Asp-β-Ala-Gly-Arg-Arg- Lys-Arg-Arg-Gln-Arg-Arg-Arg-NH₂ (SEQ ID NO: 91) Ac-c(Cys-Glu-His-D-2-Nal-Arg-2-Nal-Ala- 5.66 1.40 0.446 6.23 Cys)-Pro-Pro-Lys-Asp-β-Ala-Gly-Arg-Lys- Arg-Arg-Arg-Gln-Arg-Arg-Arg-NH₂ (SEQ ID NO: 92) Ac-Nle-c(Cys-D-Ala-His-D-Phe-Arg-Trp- 0.211 0.665 0.635 118 Cys)-(Doc)2-Tyr-Gly-Arg-Lys-Lys-Arg-Arg- Gln-Arg-Arg-Arg-NH₂ (SEQ ID NO: 136) Ac-Nle-c(Cys-D-Ala-His-D-Phe-Arg-Trp- 0.351 0.891 0.503 102 Cys)-β-Ala-Tyr-Gly-Arg-Lys-Lys-Arg-Gln- Arg-Arg-Arg-Arg-NH₂ (SEQ ID NO: 137) Ac-Nle-c(Cys-D-Ala-His-D-Phe-Arg-Trp- 0.209 0.699 0.596 137 Cys)-Doc-Tyr-Gly-Arg-Lys-Lys-Arg-Arg- Gln-Arg-Arg-Arg-NH₂(SEQ ID NO: 136) Ac-Nle-c(Cys-D-Ala-His-D-Phe-Arg-Trp- 0.439 1.52 0.476 115 Cys)-β-Ala-Gly-Arg-Arg-Arg-Arg-Arg-Gln- Arg-Arg-Arg-NH₂(SEQ ID NO: 138) Ac-Nle-c(Cys-D-Ala-His-D-Phe-Arg-Trp- 0.821 2.50 0.700 148 Cys)-β-Ala-Arg-Arg-Arg-Arg-Arg-Gln-Arg- Arg-Arg-NH₂(SEQ ID NO: 138) Ac-Nle-c(Cys-D-Ala-His-D-Phe-Arg-Trp- 0.406 1.11 0.602 131 Cys)-β-Ala-Tyr-Gly-Arg-Arg-Arg-Arg-Arg- Gln-Arg-Arg-Arg-NH₂ (SEQ ID NO: 139) Ac-Nle-c(Cys-D-Ala-His-D-Phe-Arg-Trp- 1.27 4.63 1.51 220 Cys)-β-Ala-Gly-Arg-Arg-Arg-Arg-Arg-Gln- Arg-Arg-Arg-Arg-NH₂ (SEQ ID NO: 139) Ac-c(Cys-Glu-His-D-2-Nal-Arg-2-Nal-β-Ala- 2058 113 10.7 239 Cys)-Pro-Pro-Lys-Asp-NH₂ (SEQ ID NO: 270) Ac-c(Cys-Glu-His-D-2-Nal-Arg-2-Nal-Aib- 1818 306 5.87 979 Cys)-Pro-Pro-Lys-Asp-NH₂ (SEQ ID NO: 270) Ac-c(Cys-Glu-His-D-2-Nal-Arg-1-Nal-Ala- 1.75 1.74 0.15 16.8 Cys)-Pro-Pro-Lys-Asp-β-Ala-Tyr-Gly-Arg- Arg-Lys-Arg-Arg-Gln-Arg-Arg-Arg-NH₂ (SEQ ID NO: 95) Ac-c(Cys-Glu-His-D-2-Nal-Arg-1-Nal-Ala- 1.50 1.61 0.301 10.4 Cys)-Pro-Pro-Lys-Asp-β-Ala-Tyr-Gly-Arg- Lys-Arg-Arg-Arg-Gln-Arg-Arg-Arg-NH₂ (SEQ ID NO: 96) Ac-c(Cys-Glu-His-D-2-Nal-Arg-1-Nal-Ala- 1.81 2.08 0.305 19.3 Cys)-Pro-Pro-Lys-Asp-β-Ala-Gly-Arg-Arg- Lys-Arg-Arg-Gln-Arg-Arg-Arg-NH₂ (SEQ ID NO: 97) Ac-c(Cys-Glu-His-D-2-Nal-Arg-1-Nal-Ala- 2.69 2.59 0.243 19.2 Cys)-Pro-Pro-Lys-Asp-β-Ala-Gly-Arg-Lys- Arg-Arg-Arg-Gln-Arg-Arg-Arg-NH₂ (SEQ ID NO: 92) Ac-c(Cys-Glu-His-D-2-Nal-Arg-2-Nal-Ala- 2.25 0.62 0.303 2.77 Cys)-Pro-Pro-Lys-Asp-β-Ala-Arg-Lys-Arg- Arg-Arg-Gln-Arg-Arg-Arg-NH₂ (SEQ ID NO: 99) Ac-c(Cys-Glu-His-D-2-Nal-Arg-2-Nal-Ala- 1.49 0.604 0.865 3.13 Cys)-Pro-Pro-Lys-Asp-β-Ala-Tyr-Gly-Arg- Lys-Arg-Arg-Arg-Gln-Arg-Arg-Arg- NH₂(SEQ ID NO: 101) Ac-c(Cys-Glu-His-D-2-Nal-Arg-Bal-Ala-Cys)- 3.28 1.95 0.575 15.5 Pro-Pro-Lys-Asp-β-Ala-Arg-Lys-Arg-Arg- Arg-Gln-Arg-Arg-Arg-NH₂(SEQ ID NO: 105) Ac-c(Cys-Glu-His-D-2-Nal-Arg-Bal-Ala-Cys)- 2.24 1.57 0.437 16.4 Pro-Pro-Lys-Asp-β-Ala-Tyr-Gly-Arg-Arg- Lys-Arg-Arg-Gln-Arg-Arg-Arg-NH₂ (SEQ ID NO: 100) Ac-c(Cys-Glu-His-D-2-Nal-Arg-Bal-Ala-Cys)- 2.14 1.12 0.624 11.9 Pro-Pro-Lys-Asp-β-Ala-Tyr-Gly-Arg-Lys- Arg-Arg-Arg-Gln-Arg-Arg-Arg-NH₂ (SEQ ID NO: 101) Ac-c(Cys-Glu-His-D-2-Nal-Arg-Bal-Ala-Cys)- 2.50 1.59 0.573 15.7 Pro-Pro-Lys-Asp-β-Ala-Gly-Arg-Arg-Lys- Arg-Arg-Gln-Arg-Arg-Arg-NH₂ (SEQ ID NO: 102) Ac-c(Cys-Glu-His-D-2-Nal-Arg-Bal-Ala-Cys)- 3.00 1.70 0.442 15.5 Pro-Pro-Lys-Asp-β-Ala-Arg-Arg-Lys-Arg- Arg-Gln-Arg-Arg-Arg-NH₂ (SEQ ID NO: 104) Ac-c(Cys-Glu-His-D-2-Nal-Arg-Bal-Ala-Cys)- 4.29 2.15 0.425 15.5 Pro-Pro-Lys-Asp-β-Ala-Gly-Arg-Lys-Arg- Arg-Arg-Gln-Arg-Arg-Arg-NH₂ (SEQ ID NO: 103) Ac-Nle-c(Cys-D-Ala-His-D-Phe-Arg-Trp- 0.410 0.837 0.246 56.3 Cys)-β-Ala-Tyr-Gly-Arg-Arg-Lys-Arg-Arg- Gln-Arg-Arg-Arg-NH₂ (SEQ ID NO: 141) Ac-Nle-c(Cys-D-Ala-His-D-Phe-Arg-Trp- 0.572 1.07 0.210 63.6 Cys)-β-Ala-Tyr-Gly-Arg-Lys-Arg-Arg-Arg- Gln-Arg-Arg-Arg-NH₂ (SEQ ID NO: 142) Ac-Nle-c(Cys-D-Ala-His-D-Phe-Arg-Trp- 0.475 0.800 0.196 53.8 Cys)-β-Ala-Gly-Arg-Arg-Lys-Arg-Arg-Gln- Arg-Arg-Arg-NH₂ (SEQ ID NO: 141) Ac-Nle-c(Cys-D-Ala-His-D-Phe-Arg-Trp- 0.779 1.21 0.293 56.0 Cys)-β-Ala-Gly-Arg-Lys-Arg-Arg-Arg-Gln- Arg-Arg-Arg-NH₂ (SEQ ID NO: 142) Ac-Nle-c(Cys-D-Ala-His-D-Phe-Arg-Trp- 0.212 1.23 0.484 58.5 Cys)-β-Ala-Arg-Arg-Lys-Arg-Arg-Gln-Arg- Arg-Arg-NH₂ (SEQ ID NO: 143) Ac-Nle-c(Cys-D-Ala-His-D-Phe-Arg-Trp- 0.778 1.22 0.468 47.0 Cys)-β-Ala-Arg-Lys-Arg-Arg-Arg-Gln-Arg- Arg-Arg-NH₂ (SEQ ID NO: 144)

TABLE 7 Binding Constants for Formula (V) Examples Ki Ki Ki Ki Formula (V) Compounds hMC1 hMC3 hMC4 hMC5 c[Hydantoin(C(O)-(Cys-D-Ala))-His-D-Phe- 230 7590 126 7020 Arg-Trp-Cys]-NH₂ (SEQ ID NO: 271) c[Hydantoin(C(O)-(Glu-D-Ala))-His-D-Phe- 72.6 1920 45.2 >10000 Arg-Trp-Lys]-NH₂ (SEQ ID NO: 276) c[Hydantoin(C(O)-(Glu-D-Ala))-His-D-Phe- 60.4 2840 52.4 >10000 Arg-Trp-Orn]-NH₂ (SEQ ID NO: 276) c[Hydantoin(C(O)-(Glu-D-Ala))-His-D-Phe- 28 90.5 12.7 877 Arg-Trp-Dab]-NH₂ (SEQ ID NO: 276) c[Hydantoin(C(O)-(Glu-D-Ala))-His-D-Phe- 16.4 863 4.97 >10000 Arg-Trp-Dap]-NH₂ (SEQ ID NO: 276) c[Hydantoin(C(O)-(Asp-D-Ala))-His-D-Phe- 37.7 576 7.81 6400 Arg-Trp-Orn]-NH₂ (SEQ ID NO: 273) c[Hydantoin(C(O)-(Asp-D-Ala))-His-D-Phe- 66.6 1820 19.9 >10000 Arg-Trp-Dap]-NH₂ (SEQ ID NO: 273) c[Hydantoin(C(O)-(Asp-His))-D-2-Nal-Arg- 200 68.8 6.63 142 Trp-Lys]-NH₂ (SEQ ID NO: 275) c[Hydantoin(C(O)-(Asp-Aic))-D-2-Nal-Arg- 9028 2628 35.8 1156 Trp-Lys]-NH₂ (SEQ ID NO: 275) c[Hydantoin(C(O)-(Asp-A5c))-D-2-Nal-Arg- 9938 2390 44.6 1103 Trp-Lys]-NH₂ (SEQ ID NO: 275) c[Hydantoin(C(O)-(Asp-A6c))-D-2-Nal-Arg- 2170 1479 16.5 451 Trp-Lys]-NH₂ (SEQ ID NO: 275) c[Hydantoin(C(O)-(Asp-Apc))-D-2-Nal-Arg- 1276 2756 266 1096 Trp-Lys]-NH₂ (SEQ ID NO: 275) c[Hydantoin(C(O)-(Asp-A3c))-D-2-Nal-Arg- 7567 1922 420 2879 Trp-Lys]-NH₂ (SEQ ID NO: 275) Formula (V) Compounds hMC1 hMC3 hMC4 hMC5 Binding Constants for Formula (VI) Examples Ki Ki Ki Ki Formula (VI) Compounds hMC1 hMC3 hMC4 hMC5 Hydantoin(C(O)-(Nle-Gly))-c(Cys-Glu-His-D- 14.3 198 5.76 67.8 Phe-Arg-Trp-Cys)-NH₂ (SEQ ID NO: 278) Hydantoin(C(O)-(Gly-Gly))-c(Cys-Glu-His-D- 11.9 311 5.41 73.9 Phe-Arg-Trp-Cys)-NH₂ (SEQ ID NO: 278) Hydantoin(C(O)-(A6c-Nle))-c(Cys-D-Ala-His- 31.6 224 19.6 2500 D-Phe-Arg-Trp-Cys)-NH₂ (SEQ ID NO: 284) Hydantoin(C(O)-(D-Ala-Nle))-c(Cys-D-Ala- 16.0 63.9 8.64 1820 His-D-Phe-Arg-Trp-Cys)-NH₂ (SEQ ID NO: 284) Hydantoin(C(O)-(Val-Nle))-c(Cys-D-Ala-His- 33.7 132 40.2 3210 D-Phe-Arg-Trp-Cys)-NH₂ (SEQ ID NO: 284) Hydantoin(C(O)-(Leu-Nle))-c(Cys-D-Ala-His- 48.3 534 74.1 3290 D-Phe-Arg-Trp-Cys)-NH₂ (SEQ ID NO: 284) Hydantoin(C(O)-(Cha-Nle))-c(Cys-D-Ala-His- 40.8 870 137 3560 D-Phe-Arg-Trp-Cys)-NH₂ (SEQ ID NO: 284) Hydantoin(C(O)-(Aib-Nle))-c(Cys-D-Ala-His- 17.7 73.6 8.40 2120 D-Phe-Arg-Trp-Cys)-NH₂ (SEQ ID NO: 284) Hydantoin(C(O)-(Nle-Gly))-c(Cys-D-Ala-His- 7.92 46.4 6.70 21.3 D-Phe-Arg-Trp-Cys)-NH₂ (SEQ ID NO: 279) Hydantoin(C(O)-(Gly-Gly))-c(Cys-D-Ala-His- 20.9 69.7 8.32 50.0 D-Phe-Arg-Trp-Cys)-NH₂ (SEQ ID NO: 279) Hydantoin(C(O)-(Nle-Gly))-c(Cys-D-Ala-His- 12.9 38.5 3.53 27.1 D-Phe-Arg-Trp-Pen)-NH₂ (SEQ ID NO: 280) Hydantoin(C(O)-(Gly-Gly))-c(Cys-D-Ala-His- 127 811 10.4 381 D-Phe-Arg-Trp-Pen)-NH₂ (SEQ ID NO: 280) Hydantoin(C(O)-(Ala-Gly))-c(Cys-D-Ala-His- 13.9 38.4 5.73 18.9 D-Phe-Arg-Trp-Cys)-NH₂ (SEQ ID NO: 279) Hydantoin(C(O)-(D-Ala-Gly))-c(Cys-D-Ala- 11.7 73.1 4.28 34.7 His-D-Phe-Arg-Trp-Cys)-NH₂ (SEQ ID NO: 279) Hydantoin(C(O)-(Aib-Gly))-c(Cys-D-Ala-His- 36.8 290 13.7 133 D-Phe-Arg-Trp-Cys)-NH₂ (SEQ ID NO: 279) Hydantoin(C(O)-(Val-Gly))-c(Cys-D-Ala-His- 15.3 160 8.66 33.4 D-Phe-Arg-Trp-Cys)-NH₂ (SEQ ID NO: 279) Hydantoin(C(O)-(Ile-Gly))-c(Cys-D-Ala-His- 11.6 194 11.5 28.9 D-Phe-Arg-Trp-Cys)-NH₂ (SEQ ID NO: 279) Hydantoin(C(O)-(Leu-Gly))-c(Cys-D-Ala-His- 19.3 331 26.7 44.6 D-Phe-Arg-Trp-Cys)-NH₂ (SEQ ID NO: 279) Hydantoin(C(O)-(D-Arg-Gly))-c(Cys-Glu-His- 9.49 124 2.95 2260 D-Phe-Arg-Trp-Cys)-NH₂ (SEQ ID NO: 278) Hydantoin(C(O)-(Gly-D-Arg))-c(Cys-Glu-His- 4.30 78.0 1.77 4540 D-Phe-Arg-Trp-Cys)-NH₂ (SEQ ID NO: 287) Hydantoin(C(O)-(Arg-Gly))-c(Cys-Glu-His-D- 8.59 94.1 2.44 7760 Phe-Arg-Trp-Cys)-NH₂ (SEQ ID NO: 278) Hydantoin(C(O)-(Gly-Arg))-c(Cys-Glu-His-D- 5.68 55.5 2.44 4220 Phe-Arg-Trp-Cys)-NH₂ (SEQ ID NO: 285) Hydantoin(C(O)-(Arg-Gly))-c(Cys-D-Ala-His- 2.65 41.3 4.17 650 D-Phe-Arg-Trp-Cys)-NH₂ (SEQ ID NO: 279) Hydantoin(C(O)-(D-Arg-Gly))-c(Cys-D-Ala- 3.52 48.7 5.78 872 His-D-Phe-Arg-Trp-Cys)-NH₂ (SEQ ID NO: 279) Hydantoin(C(O)-(Gly-D-Arg))-c(Cys-D-Ala- 3.51 29.2 6.04 914 His-D-Phe-Arg-Trp-Cys)-NH₂ (SEQ ID NO288) Hydantoin(C(O)-(Gly-Arg))-c(Cys-D-Ala-His- 1.14 01.7 4.53 783 D-Phe-Arg-Trp-Cys)-NH₂ (SEQ ID NO: 286) Hydantoin(C(O)-(Arg-Gly))-c(Cys-D-Ala-His- 11.9 7.43 0.195 14.6 D-2-Nal-Arg-Trp-Cys)-NH₂ (SEQ ID NO: 282) Binding Constants for Formula (VII) Examples Ki Ki Ki Ki Formula (VII) Compounds hMC1 hMC3 hMC4 hMC5 c[Hydantoin(C(O)-(Aib-Cys))-D-Ala-His-D- 47.6 1100 47.1 >10000 Phe-Arg-Trp-Cys]-NH₂ (SEQ ID NO: 290) c[Hydantoin(C(O)-(Val-Cys))-D-Ala-His-D- 21.2 730 34.5 >10000 Phe-Arg-Trp-Cys]-NH₂ (SEQ ID NO: 290) c[Hydantoin(C(O)-(Leu-Cys))-D-Ala-His-D- 47.4 1550 27.9 >10000 Phe-Arg-Trp-Cys]-NH₂ (SEQ ID NO: 290) c[Hydantoin(C(O)-(Ile-Cys))-D-Ala-His-D-Phe- 53.4 1760 41.6 >10000 Arg-Trp-Cys]-NH₂ (SEQ ID NO: 290) c[Hydantoin(C(O)-(A6c-Cys))-D-Ala-His-D- 38.5 1760 53.2 9270 Phe-Arg-Trp-Cys]-NH₂ (SEQ ID NO: 290) c[Hydantoin(C(O)-(Gly-Cys))-Glu-His-D-Phe- 15.6 305 8.92 3070 Arg-Trp-Cys]-NH₂ (SEQ ID NO: 291)

TABLE 8 Radioligand Binding Assay Data for Selected Compounds Ki Ki Ki Ki Compound hMC1-R hMC3-R hMC4-R hMC5-R Ac-Tyr-Arg-c(Cys-D-Ala-His-D-Phe- 8.53 21.2 3.72 714 Arg-Trp-Cys)-NH₂ (SEQ ID NO: 292) Ac-2-Nal-Arg-c(Cys-D-Ala-His-D-Phe- 6.09 34.9 2.02 864 Arg-Trp-Cys)-NH₂ (SEQ ID NO: 292) Ac-1-Nal-Arg-c(Cys-D-Ala-His-D-Phe- 6.27 36.4 1.53 888 Arg-Trp-Cys)-NH₂ (SEQ ID NO: 292) Ac-Phe-Arg-c(Cys-D-Ala-His-D-Phe- 1.48 14.8 2.34 491 Arg-Trp-Cys)-NH₂ (SEQ ID NO: 292) Ac-Trp-Arg-c(Cys-D-Ala-His-D-Phe- 4.7 42 2.25 1470 Arg-Trp-Cys)-NH₂ (SEQ ID NO: 292) Ac-Pff-Arg-c(Cys-D-Ala-His-D-Phe- 0.323 1.33 1.95 786 Arg-Trp-Cys)-NH₂ (SEQ ID NO: 292)

Melanocortin Functional Activity and Selectivity

The compounds of the present invention will interact preferentially (i.e., selectively) to MC-4 relative to the other melanocortin receptors. Selectivity is particularly important when the compounds are administered to humans or other animals to minimize the number of side effects associated with their administration. MC-4 selectivity of a compound is defined herein as the ratio of the EC₅₀ of the compound for an MC-1 receptor (EC₅₀−MC-1) over the EC₅₀ of the compound for the MC-3 (EC₅₀−MC-3)/MC-4 (EC₅₀−MC-4) receptor, the EC₅₀ values being measured as described above. The formulas are as follows:

MC-3 selectivity=[EC₅₀-MC-1]/[EC₅₀-MC-3]

MC-4 selectivity=[EC₅₀-MC-1]/[EC₅₀-MC-4]

A compound is defined herein as being “selective for the MC-3 receptor” when the above mentioned ratio “MC-3-selectivity” is at least about 10, preferably at least about 100, and more preferably at least about 500.

A compound is defined herein as being “selective for the MC-4 receptor” when the above mentioned ratio “MC-4-selectivity” is at least about 10, preferably at least about 100, and more preferably at least about 500.

One skilled in the art would know that procedures similar to those described herein may be used to assay the binding activities of the compounds of the invention to melanocortin receptor molecules.

Cyclic AMP Bioassay

Intracellular cyclic AMP (cAMP) levels were determined by an electrochemiluminescence (ECL) assay (Meso Scale Discovery®, Gaithersburg, Md.; referred to hereinafter as MSD). CHO-K1 cells stably expressing the hMC receptor subtypes were suspended in RMPI 1640 ® assay buffer (RMPI 1640 buffer contains 0.5 mM isobutylmethylxanthine (IBMX), and 0.2% protein cocktail (MSD blocker A)). Transgenic CHO-K1 cells stably expressing hMC receptor subtypes 1, 3, 4 or 5 were dispensed at a density of approximately 7,000 cells/well in 384-well Multi-Array® plates (MSD) containing integrated carbon electrodes and coated with anti-cAMP antibody. Increasing concentrations of the test compounds were added and the cells were incubated for approximately 40 minutes at approximately 37° C. Following this incubation, lysis buffer (HEPES-buffered saline solution with MgCl₂ and Triton X-100® at ph 7.3) containing 0.2% protein cocktail and 2.5 nM TAG™ ruthenium-labeled cAMP (MSD) was added and the cells were incubated for approximately 90 minutes at room temperature. At the end of the second incubation period read buffer (Tris-buffered solution containing an ECL co-reactant and Triton X-100 at ph 7.8) was added and the cAMP levels in the cell lysates were immediately determined by ECL detection with a Sector Imager 6000 Reader® (MSD). Data were analyzed using a computer-assisted non-linear regression analysis (XL fit; IDBS) and reported as either an EC₅₀ value or a Kb value.

EC₅₀ represents the concentration of an agonist compound needed to obtain 50% of the maximum reaction response, e.g., 50% of the maximum level of cAMP as determined using the assay described above. The Kb value reflects the potency of an antagonist and is determined by Schild analysis. In brief, concentration-response curves of an agonist are carried out in the presence of increasing concentrations of an antagonist. The Kb value is the concentration of antagonist which would produce a 2-fold shift in the concentration-response curve for an agonist. It is calculated by extrapolating the line on a Schild plot to zero on the y-axis.

A selection of compounds was tested using the above-discussed assays and the results are reported in Tables 9, 10, 11, and 12.

TABLE 9 cAMP Bioassay Data for Selected Compounds EC₅₀ EC₅₀ EC₅₀ EC₅₀ EC₅₀ hMC1-R/ SEQ ID Compound hMC1-R hMC3-R hMC4-R hMC5-R MC4-R NO: Ac-Arg-c(Cys-D- 5.79 5.25 0.313 1630 18.0 SEQ ID Ala-His-D-Phe- NO: 50 Arg-Trp-Cys)-NH₂ Ac-D-Arg-c(Cys-D- 6.17 5.6 0.397 1020 16.0 SEQ ID Ala-His-D-Phe- NO: 50 Arg-Trp-Cys)-NH₂ Ac-D-Arg-c(Cys-D- 26.5 10.5 0.493 2440 54.0 SEQ ID Ala-His-D-Phe- NO: 51 Arg-Trp-Pen)-NH₂ Ac-D-Arg-c(Cys- 8.43 32.4 0.959 2140 9.0 SEQ ID His-D-Phe-Arg- NO: 52 Trp-Gaba-Pen)-NH₂ Ac-Arg-c(Cys-His- 4.23 8.09 0.719 23.2 6.0 SEQ ID D-Phe-Arg-Trp- NO: 52 Gaba-Pen)-NH₂ Ac-Arg-c(Cys-D- 48.3 13.3 0.79 10000 61.0 SEQ ID Ala-His-D-Phe- NO: 51 Arg-Trp-Pen)-NH₂ Ac-D-Arg-c(Asp- 1.48 5.76 0.078 297 19.0 SEQ ID His-D-Phe-Arg- NO: 53 Trp-Ala-Lys)-NH₂ Ac-Arg-c(Asp-His- 1.39 2.89 0.055 467 25.0 SEQ ID D-Phe-Arg-Trp- NO: 53 Ala-Lys)-NH₂ EC₅₀ EC₅₀ EC₅₀ EC₅₀ EC₅₀ hMC1-R/ SEQ ID Compound hMC1-R hMC3-R hMC4-R hMC5-R MC4-R NO: Ac-Nle-c(Cys-D-Ala-His- 2.4 0.33 0.078 420 31 SEQ ID D-Phe-Arg-Trp-Cys)- NO: 7 NH₂ D-Phe-c(Cys-His-D- 0.35 1.1 0.11 0.37 3 SEQ ID (Et)Tyr-Arg-Trp-β-Ala- NO: 24 D-Cys)-Thr-NH₂ Nle-c(Cys-His-D-Phe- 0.31 0.27 0.018 3.1 17 SEQ ID Arg-Trp-Apn-Cys)-NH₂ NO: 27 Ac-Nle-c(Cys-His-D-Phe- 0.28 0.24 0.028 3.9 10 SEQ ID Arg-Trp-Gaba-Pen)-NH₂ NO: 32 Nle-c(Cys-His-D-Phe- 0.37 0.1 0.021 1.7 18 SEQ ID Arg-Trp-Gaba-Cys)-NH₂ NO: 34 Ac-Nle-c(Asp-His-D- 0.834 0.145 0.128 2.79 6.52 SEQ ID Phe-Arg-Trp-β-Ala-Lys)- NO: 1 NH₂ Ac-Nle-c(Cys-His-D-Phe- 0.76 0.199 0.0492 1.73 15.45 SEQ ID Arg-Trp-Apn-Cys)-NH₂ NO: 2 Ac-Cha-c(Asp-His-D- 3.26 0.189 0.0949 30.2 34.35 SEQ ID Phe-Arg-Trp-Gaba-Lys)- NO: 6 NH₂ Ac-Nle-c(Asp-His-D- 1.37 0.628 0.131 3.48 10.46 SEQ ID Phe-Arg-Trp-Gaba-Lys)- NO: 6 NH₂ Ac-hCha-c(Asp-His-D- 2.27 3.32 7.24 415 0.31 SEQ ID Phe-Arg-Trp-Gaba-Lys)- NO: 11 NH₂ Ac-Nle-c(Pen-D-Ala-His- ND 1.89 0.531 ND ND SEQ ID D-Phe-Arg-Trp-Cys)- NO: 21 NH₂ Ac-Nle-c(Cys-D-Ala-His- 14.3 2.03 0.183 2240 78.14 SEQ ID D-Phe-Arg-Trp-Pen)- NO: 22 NH₂ D-Phe-c(Cys-His-D- 0.345 2.71 5376 2.38 0.06 SEQ ID (Et)Tyr-hArg-Trp-β-Ala- NO: 24 D-Cys)-Thr-NH₂ D-Phe-c(Cys-His-D- 0.685 81.8 86.9 31.8 0.01 SEQ ID (Et)Tyr-hArg-Bip-β-Ala- NO: 26 D-Cys)-Thr-NH₂ Ac-Nle-c(Asp-D-Ala-His- 0.931 3.22 1.65 >10000 0.56 SEQ ID D-Phe-Arg-Bal-Lys)-NH₂ NO: 28 Ac-Nle-c(Cys-D-Leu-His- 3.24 0.465 0.0915 78.5 35.41 SEQ ID D-Phe-Arg-Trp-Cys)- NO: 30 NH₂ Ac-Nle-c(Cys-D-Cha- 0.819 0.541 0.453 45.3 1.81 SEQ ID His-D-Phe-Arg-Trp-Cys)- NO: 30 NH₂ EC50 Kb Kb EC50 SEQ ID Compound hMC1-R hMC3-R MC4-R hMC5-R NO: Ac-Nle-c(Cys-D-Ala-His-D-2- 17.6 12.4 38.8 11.8 SEQ ID Nal-Arg-Trp-Cys)-NH₂ NO: 16 Ac-Nle-c(Asp-His-D-2-Nal-Arg- 0.619 2.98 0.109 0.189 SEQ ID Trp-Ala-Lys)-NH₂ NO: 38 Ac-Nle-c(Asp-His-D-2-Nal-Arg- 0.913 0.536 0.346 0.489 SEQ ID Trp-β-Ala-Lys)-NH₂ NO: 38 Ac-Nle-c(Cys-His-D-2-Nal-Arg- 0.231 18.4 0.782 0.153 SEQ ID Trp-Gaba-Cys)-NH₂ NO: 39 Ac-Nle-c(Cys-His-D-2-Nal-Arg- 0.581 10.8 0.967 0.126 SEQ ID Trp-Ahx-Cys)-NH₂ NO: 39 Ac-hPhe-c(Asp-His-D-2-Nal-Arg- 0.413 9.32 0.824 0.307 SEQ ID Trp-Gaba-Lys)-NH₂ NO: 40 Ac-Cha-c(Asp-His-D-2-Nal-Arg- 1.27 3.02 0.442 0.736 SEQ ID Trp-Gaba-Lys)-NH₂ NO: 40 Ac-Nle-c(Cys-D-Ala-His-D-2- 383 61.5 53.6 2842 SEQ ID Nal-Arg-1-Nal-Cys)-NH₂ NO: 16 EC50 Kb Kb EC50 SEQ ID Compound hMC1-R hMC3-R MC4-R hMC5-R NO: Ac-Arg-c(Cys-D-Ala-His-D-2- 193 5.72 1.58 1111 SEQ ID Nal-Arg-Trp-Cys)-NH₂ NO: 49 ND = not determined

TABLE 10A EC₅₀ Kb Kb EC₅₀ Compound hMC1-R hMC3-R hMC4-R hMC5-R Ac-c(Cys-Glu-His-D-2-Nal-Arg-Trp-Ala- 66.1 33.4 0.687 6.84 Cys)-Pro-Pro-Lys-Asp-NH₂ (SEQ ID NO: 269) Tyr-Gly-Arg-Lys-Lys-Arg-Arg-Gln-Arg- ND 4500 105 ND Arg-Arg-Nle-c(Asp-His-D-2-Nal-Arg-Trp- Lys)-NH₂ (SEQ ID NO: 60) Tyr-Gly-Arg-Lys-Lys-Arg-Arg-Gln-Arg- ND 395 16.8 ND Arg-Arg-Doc-Nle-c(Asp-His-D-2-Nal-Arg- Trp-Lys)-NH₂ (SEQ ID NO: 61) Nle-c(Asp-His-D-2-Nal-Arg-Trp-Lys)-β- ND 207 18.5 ND Ala-Tyr-Gly-Arg-Lys-Lys-Arg-Arg-Gln- Arg-Arg-Arg-NH₂ (SEQ ID NO: 62) Ac-Nle-c(Asp-His-D-2-Nal-Arg-Trp-Lys)-β- ND 220 4.07 ND Ala-Tyr-Gly-Arg-Lys-Lys-Arg-Arg-Gln- Arg-Arg-Arg-NH₂ (SEQ ID NO: 62) H-Nle-c(Asp-His-D-2-Nal-Arg-Trp-Lys)- ND 261 3.11 ND Doc-Doc-Tyr-Gly-Arg-Lys-Lys-Arg-Arg- Gln-Arg-Arg-Arg-NH₂ (SEQ ID NO: 63) Ac-Nle-c(Asp-His-D-2-Nal-Arg-Trp-Lys)- ND 14.1 22.8 ND Pro-Pro-Lys-Asp-Tyr-Gly-Arg-Lys-Lys- Arg-Arg-Gln-Arg-Arg-Arg-NH₂ (SEQ ID NO: 64) Ac-c(Cys-Glu-His-D-2-Nal-Arg-Trp-Gly- ND 233 26.0 ND Cys)-Pro-Pro-Lys-Asp-Tyr-Gly-Arg-Lys- Lys-Arg-Arg-Gln-Arg-Arg-Arg-NH₂ (SEQ ID NO: 65) Ac-Nle-c(Asp-His-D-2-Nal-Arg-Trp-Lys)-β- 1.39 16.2 7.94 0.839 Ala-β-Ala-Tyr-Gly-Arg-Lys-Lys-Arg-Arg- Gln-Arg-Arg-Arg-NH₂ (SEQ ID NO: 66) Ac-Nle-c(Asp-His-D-2-Nal-Arg-Trp-Lys)- 3.65 19.4 3.73 1.61 Pro-Pro-Lys-Asp-Doc-Tyr-Gly-Arg-Lys- Lys-Arg-Arg-Gln-Arg-Arg-Arg-NH₂ (SEQ ID NO: 67) Ac-c(Cys-Glu-His-D-2-Nal-Arg-Trp-Gly- ND 17.7 1.49 ND Cys)-Pro-Pro-Lys-Asp-Doc-Tyr-Gly-Arg- Lys-Lys-Arg-Arg-Gln-Arg-Arg-Arg-NH₂ (SEQ ID NO: 68) Ac-c(Cys-Glu-His-D-2-Nal-Arg-Trp-Ala- 6.3 70.0 1.66 38.2 Cys)-Pro-Pro-Lys-Asp-β-Ala-Tyr-Gly-Arg- Lys-Lys-Arg-Arg-Gln-Arg-Arg-Arg- NH₂ (SEQ ID NO: 69) Ac-c(Cys-Glu-His-D-2-Nal-Arg-Trp-Ala- 12.1 30.3 1.81 70.0 Cys)-Pro-Pro-Lys-Asp-Doc-Tyr-Gly-Arg- Lys-Lys-Arg-Arg-Gln-Arg-Arg-Arg-NH₂ (SEQ ID NO: 69) Ac-c(Cys-Glu-His-D-2-Nal-Arg-2-Nal-Ala- 33.6 140 12.2 66.9 Cys)-Pro-Pro-Lys-Asp-NH₂ (SEQ ID NO: 269) Ac-c(Cys-Glu-His-D-2-Nal-Arg-1-Nal-Ala- 269 105 5.92 104 Cys)-Pro-Pro-Lys-Asp-NH₂ (SEQ ID NO: 269) Ac-c Cys-Glu-His-D-2-Nal-Arg-Bal-Ala- 690 70.7 4.56 177 Cys)-Pro-Pro-Lys-Asp-NH₂ (SEQ ID NO: 269) Ac-Nle-c(Asp-His-D-2-Nal-Arg-Trp-Lys)- 3.23 8.97 4.61 2.86 Doc-Doc-Tyr-Gly-Arg-Lys-Lys-Arg-Arg- Gln-Arg-Arg-Arg-NH₂ (SEQ ID NO: 70) Ac-c(Cys-Glu-His-D-2-Nal-Arg-Bal-Ala- 52.0 170 6.14 328 Cys)-Pro-Pro-Lys-Asp-β-Ala-Arg-Arg-Arg- Arg-Arg-Gln-Arg-Arg-Arg-NH₂ (SEQ ID NO: 72) Ac-c(Cys-Glu-His-D-2-Nal-Arg-Bal-Ala- 146 104 32.0 1400 Cys)-Pro-Pro-Lys-Asp-β-Ala-Gly-Arg-Arg- Arg-Arg-Arg-Gln-Arg-Arg-Arg-NH₂ (SEQ ID NO: 73) Ac-c(Cys-Glu-His-D-2-Nal-Arg-Bal-Ala- 114 44.6 28.4 879 Cys)-Pro-Pro-Lys-Asp-β-Ala-Tyr-Gly-Arg- Arg-Arg-Arg-Arg-Gln-Arg-Arg-Arg-NH₂ (SEQ ID NO: 74) Ac-c(Cys-Glu-His-D-2-Nal-Arg-Bal-Ala- 67.1 439 46.5 582 Cys)-Pro-Pro-Lys-Asp-β-Ala-Tyr-Aib-Arg- Lys-Lys-Arg-Arg-Gln-Arg-Arg-Arg-NH₂ (SEQ ID NO: 79) Ac-c(Cys-Glu-His-D-2-Nal-Arg-1-Nal-Ala- 144 116 8.93 819 Cys)-Pro-Pro-Arg-Asp-β-Ala-Arg-Arg-Arg- Arg-Arg-Gln-Arg-Arg-Arg-NH₂ (SEQ ID NO: 80) Ac-c(Cys-Glu-His-D-2-Nal-Arg-1-Nal-Ala- 36.0 46.5 11.4 56.1 Cys)-Pro-Pro-Lys-Asp-β-Ala-Arg-Arg-Arg- Arg-Arg-Gln-Arg-Arg-Arg-NH₂ (SEQ ID NO: 80) Ac-c(Cys-Glu-His-D-2-Nal-Arg-1-Nal-Ala- 93.0 71 15.9 >10000 Cys)-Pro-Pro-Lys-Asp-β-Ala-Arg-Arg-Arg- Arg-Arg-Arg-Gln-Arg-Arg-Arg-NH₂ (SEQ ID NO: 81) Ac-c(Cys-Glu-His-D-2-Nal-Arg-2-Nal-Ala- 39.7 30.9 6.66 501 Cys)-Pro-Pro-Arg-Asp-β-Ala-Arg-Arg-Arg- Arg-Arg-Gln-Arg-Arg-Arg-NH₂ (SEQ ID NO: 82) Ac-c(Cys-Glu-His-D-2-Nal-Arg-2-Nal-Ala- 35.2 22.9 12.6 199 Cys)-Pro-Pro-Lys-Asp-β-Ala-Arg-Arg-Arg- Arg-Arg-Gln-Arg-Arg-Arg-NH₂ (SEQ ID NO: 82) Ac-c(Cys-Glu-His-D-2-Nal-Arg-2-Nal-Ala- 29.1 13.6 13.4 204 Cys)-Pro-Pro-Lys-Asp-β-Ala-Arg-Arg-Arg- Arg-Arg-Arg-Gln-Arg-Arg-Arg-NH₂ (SEQ ID NO: 81) Ac-c(Cys-Glu-His-D-2-Nal-Arg-Bal-Ala- 86.1 41.7 19.4 2360 Cys)-Pro-Pro-Arg-Asp-β-Ala-Arg-Arg-Arg- Arg-Arg-Arg-Gln-Arg-Arg-Arg-NH₂ (SEQ ID NO: 83) Ac-c(Cys-Glu-His-D-2-Nal-Arg-Bal-Ala- 38.3 20.2 21.2 >10000 Cys)-Pro-Pro-Arg-Asp-β-Ala-Arg-Arg-Arg- Arg-Arg-Gln-Arg-Arg-Arg-NH₂ (SEQ ID NO: 84) Ac-c(Cys-Glu-His-D-2-Nal-Arg-Bal-Ala- 68.6 153 33.2 >10000 Cys)-Pro-Pro-Lys-Asp-β-Ala-Arg-Arg-Arg- Arg-Arg-Arg-Gln-Arg-Arg-Arg-NH₂ (SEQ ID NO: 83) Ac-c(Cys-Glu-His-D-2-Nal-Arg-1-Nal-Ala- 70.4 286 18.6 >10000 Cys)-Pro-Pro-Lys-Asp-β-Ala-Arg-Arg-Lys- Arg-Arg-Gln-Arg-Arg-Arg-NH₂ (SEQ ID NO: 88) Ac-c(Cys-Glu-His-D-2-Nal-Arg-1-Nal-Ala- 33.1 65.1 15.3 1720 Cys)-Pro-Pro-Lys-Asp-β-Ala-Arg-Lys-Arg- Arg-Arg-Gln-Arg-Arg-Arg-NH₂ (SEQ ID NO: 89) Ac-c(Cys-Glu-His-D-2-Nal-Arg-2-Nal-Ala- 88.2 10.6 17.4 514 Cys)-Pro-Pro-Lys-Asp-β-Ala-Arg-Arg-Lys- Arg-Arg-Gln-Arg-Arg-Arg-NH₂ (SEQ ID NO: 88) Ac-c(Cys-Glu-His-D-2-Nal-Arg-2-Nal-Ala- 58.7 39.3 10.3 460 Cys)-Pro-Pro-Lys-Asp-β-Ala-Tyr-Gly-Arg- Arg-Lys-Arg-Arg-Gln-Arg-Arg-Arg-NH₂ (SEQ ID NO: 90) Ac-c(Cys-Glu-His-D-2-Nal-Arg-2-Nal-Ala- 45.4 12.7 12.7 162 Cys)-Pro-Pro-Lys-Asp-β-Ala-Gly-Arg-Arg- Lys-Arg-Arg-Gln-Arg-Arg-Arg-NH₂ (SEQ ID NO: 91) Ac-c(Cys-Glu-His-D-2-Nal-Arg-2-Nal-Ala- 309 22.8 17.1 570 Cys)-Pro-Pro-Lys-Asp-β-Ala-Gly-Arg-Lys- Arg-Arg-Arg-Gln-Arg-Arg-Arg-NH₂ (SEQ ID NO: 92) Ac-Nle-c(Cys-D-Ala-His-D-Phe-Arg-Trp- 7.86 10.5 0.843 4900 Cys)-β-Ala-Tyr-Gly-Arg-Arg-Arg-Arg-Arg- Gln-Arg-Arg-Arg-NH₂ (SEQ ID NO: 139) Ac-c(Cys-Glu-His-D-2-Nal-Arg-2-Nal-Ala- 29.7 25.6 7.37 82.9 Cys)-Pro-Pro-Lys-Asp-β-Ala-Tyr-Gly-Arg- Lys-Lys-Arg-Arg-Gln-Arg-Arg-Arg-NH₂ (SEQ ID NO: 71) Ac-c(Cys-Glu-His-D-2-Nal-Arg-Trp-Ala- 15.2 14.6 4.52 36.8 Cys)-Pro-Pro-Lys-Asp-βAla-Tyr-Gly-Arg- Lys-Lys-Arg-Gln-Arg-Arg-Arg-Arg-NH₂ (SEQ ID NO: 75) Ac-c(Cys-Glu-His-D-2-Nal-Arg-Trp-Ala- 6.7 9.38 11.7 46.2 Cys)-Pro-Pro-Lys-Asp-β-Ala-Tyr-Gly-Arg- Lys-Lys-Gln-Arg-Arg-Arg-Arg-Arg-NH₂ (SEQ ID NO: 76) Ac-c(Cys-Glu-His-D-2-Nal-Arg-Trp-Ala- 7.9 41.7 10.9 62.4 Cys)-Pro-Pro-Lys-Asp-β-Ala-Tyr-Gly-Arg- Lys-Gln-Lys-Arg-Arg-Arg-Arg-Arg-NH₂ (SEQ ID NO: 77) Ac-c(Cys-Glu-His-D-2-Nal-Arg-Trp-Ala- 16.9 36.0 7.12 58.9 Cys)-Pro-Pro-Lys-Asp-β-Ala-Tyr-Gly-Arg- Lys-Lys-Arg-Arg-Arg-Arg-Gln-Arg-NH₂ (SEQ ID NO: 78) Ac-c(Cys-Glu-His-D-2-Nal-Arg-Trp-Ala- 16.4 20.8 7.31 44.2 Cys)-Pro-Pro-Lys-Asp-β-Ala-Tyr-Gly-Arg- Lys-Lys-Arg-Arg-Arg-Gln-Arg-Arg-NH₂ (SEQ ID NO: 85) Ac-c(Cys-Glu-His-D-2-Nal-Arg-Trp-Ala- 12.0 13.7 9.38 54.2 Cys)-Pro-Pro-Lys-Asp-β-Ala-Tyr-Gly-Arg- Gln-Lys-Lys-Arg-Arg-Arg-Arg-Arg-NH₂ (SEQ ID NO: 86) Ac-c(Cys-Glu-His-D-2-Nal-Arg-Trp-Ala- 7.5 12.2 7.61 51.7 Cys)-Pro-Pro-Lys-Asp-β-Ala-Tyr-Gly-Arg- Lys-Lys-Arg-Arg-Arg-Arg-Arg-Gln- NH₂ (SEQ ID NO: 87) Ac-c(Cys-Glu-His-D-2-Nal-Arg-1-Nal-Ala- 43.3 215 5.87 1286 Cys)-Pro-Pro-Lys-Asp-β-Ala-Tyr-Gly-Arg- Lys-Lys-Arg-Arg-Gln-Arg-Arg-Arg-NH₂ (SEQ ID NO: 71) Ac-c(Cys-Glu-His-D-2-Nal-Arg-Bal-Ala- 37.9 112 41.1 1798 Cys)-Pro-Pro-Lys-Asp-β-Ala-Tyr-Gly-Arg- Lys-Lys-Arg-Arg-Gln-Arg-Arg-Arg-NH₂ (SEQ ID NO: 71) EC50 EC50 EC50 EC50 Compound hMC1-R hMC3-R hMC4-R hMC5-R Ac-Nle-c(Cys-D-Ala-His-D-Phe-Arg-Trp- 4.70 4.56 0.634 147 Cys)-(Doc)2-Tyr-Gly-Arg-Lys-Lys-Arg- Arg-Gln-Arg-Arg-Arg-NH₂ (SEQ ID NO: 136) Ac-Nle-c(Cys-D-Ala-His-D-Phe-Arg-Trp- 5.90 7.73 1.02 2890 Cys)-β-Ala-Tyr-Gly-Arg-Lys-Lys-Arg-Gln- Arg-Arg-Arg-Arg-NH₂ (SEQ ID NO: 137) Ac-Nle-c(Cys-D-Ala-His-D-Phe-Arg-Trp- 0.481 7.32 0.964 2010 Cys)-β-Ala-Gly-Arg-Arg-Arg-Arg-Arg-Gln- Arg-Arg-Arg-NH₂ (SEQ ID NO: 136) Ac-Nle-c(Cys-D-Ala-His-D-Phe-Arg-Trp- 7.15 9.37 1.25 1570 Cys)-β-Ala-Arg-Arg-Arg-Arg-Arg-Gln-Arg- Arg-Arg-NH₂ (SEQ ID NO: 138) EC₅₀ Kb Kb EC₅₀ Compound hMC1-R hMC3-R hMC4-R hMC5-R Ac-c(Cys-Glu-His-D-2-Nal-Arg-2-Nal-β- ND ND ND ND Ala-Cys)-Pro-Pro-Lys-Asp-NH₂ (SEQ ID NO: 270) Ac-c(Cys-Glu-His-D-2-Nal-Arg-2-Nal-Aib- 770 221 4.52 869 Cys)-Pro-Pro-Lys-Asp-NH₂ (SEQ ID NO: 270) Ac-c(Cys-Glu-His-D-2-Nal-Arg-1-Nal-Ala- 29 22.6 16.7 173 Cys)-Pro-Pro-Lys-Asp-β-Ala-Tyr-Gly-Arg- Arg-Lys-Arg-Arg-Gln-Arg-Arg-Arg-NH₂ (SEQ ID NO: 95) Ac-c(Cys-Glu-His-D-2-Nal-Arg-1-Nal-Ala- 102 26.3 14.6 261 Cys)-Pro-Pro-Lys-Asp-β-Ala-Tyr-Gly-Arg- Lys-Arg-Arg-Arg-Gln-Arg-Arg-Arg-NH₂ (SEQ ID NO: 96) Ac-c(Cys-Glu-His-D-2-Nal-Arg-1-Nal-Ala- 26.6 101 9.34 351 Cys)-Pro-Pro-Lys-Asp-β-Ala-Gly-Arg-Arg- Lys-Arg-Arg-Gln-Arg-Arg-Arg-NH₂ (SEQ ID NO: 97) Ac-c(Cys-Glu-His-D-2-Nal-Arg-1-Nal-Ala- 45.5 181 6.35 149 Cys)-Pro-Pro-Lys-Asp-β-Ala-Gly-Arg-Lys- Arg-Arg-Arg-Gln-Arg-Arg-Arg-NH₂ (SEQ ID NO: 92) Ac-c(Cys-Glu-His-D-2-Nal-Arg-2-Nal-Ala- 23.7 9.22 5.87 39.7 Cys)-Pro-Pro-Lys-Asp-β-Ala-Arg-Lys-Arg- Arg-Arg-Gln-Arg-Arg-Arg-NH₂ (SEQ ID NO: 99) Ac-c(Cys-Glu-His-D-2-Nal-Arg-2-Nal-Ala- 34.7 15.0 8.68 28.2 Cys)-Pro-Pro-Lys-Asp-β-Ala-Tyr-Gly-Arg- Lys-Arg-Arg-Arg-Gln-Arg-Arg-Arg-NH₂ (SEQ ID NO: 101) Ac-c(Cys-Glu-His-D-2-Nal-Arg-Bal-Ala- 19.1 106 4.59 100 Cys)-Pro-Pro-Lys-Asp-β-Ala-Arg-Lys-Arg- Arg-Arg-Gln-Arg-Arg-Arg-NH₂ (SEQ ID NO: 105) Ac-c(Cys-Glu-His-D-2-Nal-Arg-Bal-Ala- 19.8 37.8 8.43 158 Cys)-Pro-Pro-Lys-Asp-β-Ala-Tyr-Gly-Arg- Arg-Lys-Arg-Arg-Gln-Arg-Arg-Arg- NH₂ (SEQ ID NO: 100) Ac-c(Cys-Glu-His-D-2-Nal-Arg-Bal-Ala- 11.2 52.1 9.45 95.7 Cys)-Pro-Pro-Lys-Asp-β-Ala-Tyr-Gly-Arg- Lys-Arg-Arg-Arg-Gln-Arg-Arg-Arg-NH₂ (SEQ ID NO: 101) Ac-c(Cys-Glu-His-D-2-Nal-Arg-Bal-Ala- 33.8 93.6 4.42 89.5 Cys)-Pro-Pro-Lys-Asp-β-Ala-Gly-Arg-Arg- Lys-Arg-Arg-Gln-Arg-Arg-Arg-NH₂ (SEQ ID NO: 102) Ac-c(Cys-Glu-His-D-2-Nal-Arg-Bal-Ala- 232 68.8 10.0 250 Cys)-Pro-Pro-Lys-Asp-β-Ala-Arg-Arg-Lys- Arg-Arg-Gln-Arg-Arg-Arg-NH₂ (SEQ ID NO: 104) Ac-c(Cys-Glu-His-D-2-Nal-Arg-Bal-Ala- 32.2 98.3 5.23 194 Cys)-Pro-Pro-Lys-Asp-β-Ala-Gly-Arg-Lys- Arg-Arg-Arg-Gln-Arg-Arg-Arg-NH₂ (SEQ ID NO: 103) EC50 EC50 EC50 EC50 Compound hMC1-R hMC3-R hMC4-R hMC5-R Ac-Nle-c(Cys-D-Ala-His-D-Phe-Arg-Trp- 5.66 4.70 0.422 1551 Cys)-β-Ala-Tyr-Gly-Arg-Arg-Lys-Arg-Arg- Gln-Arg-Arg-Arg-NH₂ (SEQ ID NO: 141) Ac-Nle-c(Cys-D-Ala-His-D-Phe-Arg-Trp- 7.57 4.18 0.600 1792 Cys)-β-Ala-Tyr-Gly-Arg-Lys-Arg-Arg-Arg- Gln-Arg-Arg-Arg-NH₂ (SEQ ID NO: 142) Ac-Nle-c(Cys-D-Ala-His-D-Phe-Arg-Trp- 2.36 2.74 0.260 500 Cys)-β-Ala-Gly-Arg-Arg-Lys-Arg-Arg- Gln-Arg-Arg-Arg-NH₂ (SEQ ID NO: 141) Ac-Nle-c(Cys-D-Ala-His-D-Phe-Arg-Trp- 2.81 3.29 0.298 566 Cys)-β-Ala-Gly-Arg-Lys-Arg-Arg-Arg- Gln-Arg-Arg-Arg-NH₂ (SEQ ID NO: 142) Ac-Nle-c(Cys-D-Ala-His-D-Phe-Arg-Trp- 1.86 1.39 0.367 165 Cys)-β-Ala-Arg-Arg-Lys-Arg-Arg-Gln- Arg-Arg-Arg-NH₂ (SEQ ID NO: 143) Ac-Nle-c(Cys-D-Ala-His-D-Phe-Arg-Trp- 2.06 1.61 0.394 199 Cys)-β-Ala-Arg-Lys-Arg-Arg-Arg-Gln- Arg-Arg-Arg-NH₂ (SEQ ID NO: 144) ND = not determined

TABLE 11 Intracellular Cyclic AMP (cAMP) Levels for Formula (I) Examples EC₅₀ EC₅₀ EC₅₀ EC₅₀ hMC1 hMC3 hMC4 hMC5 Formula (V) Compounds c[Hydantoin(C(O)-(Cys-D-Ala))-His-D-Phe- — 218 5.42 — Arg-Trp-Cys]-NH₂ (SEQ ID NO: 271) c[Hydantoin(C(O)-(Glu-D-Ala))-His-D-Phe- — 22.3 3.62 — Arg-Trp-Lys]-NH₂ (SEQ ID NO: 276) c[Hydantoin(C(O)-(Glu-D-Ala))-His-D-Phe- — 39.2 4.94 — Arg-Trp-Orn]-NH₂ (SEQ ID NO: 276) c[Hydantoin(C(O)-(Glu-D-Ala))-His-D-Phe- 56.7 18.2 0.182 >10000 Arg-Trp-Dap]-NH₂ (SEQ ID NO: 276) c[Hydantoin(C(O)-(Asp-D-Ala))-His-D- 56.6 88.6 4.50 9300 Phe-Arg-Trp-Orn]-NH₂ (SEQ ID NO: 273) c[Hydantoin(C(O)-(Asp-D-Ala))-His-D- — 49.3 2.12 — Phe-Arg-Trp-Dap]-NH₂ (SEQ ID NO: 273) Formula (VI) Compounds Hydantoin(C(O)-(Nle-Gly))-c(Cys-Glu-His- 54.3 12.2 0.177 >10000 D-Phe-Arg-Trp-Cys)-NH₂ (SEQ ID NO: 278) Hydantoin(C(O)-(Gly-Gly))-c(Cys-Glu-His- 124 8.05 0.214 >10000 D-Phe-Arg-Trp-Cys)-NH₂ (SEQ ID NO: 278) Hydantoin(C(O)-(A6c-Nle))-c(Cys-D-Ala- — 4.89 1.80 — His-D-Phe-Arg-Trp-Cys)-NH₂ (SEQ ID NO: 284) Hydantoin(C(O)-(D-Ala-Nle))-c(Cys-D-Ala- — 2.56 1.47 — His-D-Phe-Arg-Trp-Cys)-NH₂ (SEQ ID NO: 284) Hydantoin(C(O)-(Val-Nle))-c(Cys-D-Ala- — 4.61 0.977 — His-D-Phe-Arg-Trp-Cys)-NH₂ (SEQ ID NO: 284) Hydantoin(C(O)-(Leu-Nle))-c(Cys-D-Ala- — 9.68 1.83 — His-D-Phe-Arg-Trp-Cys)-NH₂ (SEQ ID NO: 284) Hydantoin(C(O)-(Cha-Nle))-c(Cys-D-Ala- — 9.97 13.9 — His-D-Phe-Arg-Trp-Cys)-NH₂ (SEQ ID NO: 284) Hydantoin(C(O)-(Gly-Gly))-c(Cys-D-Ala- 14.2 2.46 0.336 201 His-D-Phe-Arg-Trp-Cys)-NH₂ (SEQ ID NO: 279) Hydantoin(C(O)-(Nle-Gly))-c(Cys-D-Ala- 17.0 21.5 0.584 352 His-D-Phe-Arg-Trp-Pen)-NH₂ (SEQ ID NO: 280) Hydantoin(C(O)-(Gly-Gly))-c(Cys-D-Ala- 40.2 8.90 0.495 8300 His-D-Phe-Arg-Trp-Pen)-NH₂ (SEQ ID NO: 280) Hydantoin(C(O)-(Ala-Gly))-c(Cys-D-Ala- 17.6 2.23 0.241 516 His-D-Phe-Arg-Trp-Cys)-NH₂ (SEQ ID NO: 279) Hydantoin(C(O)-(D-Ala-Gly))-c(Cys-D-Ala- 4.70 2.22 0.309 355 His-D-Phe-Arg-Trp-Cys)-NH₂ (SEQ ID NO: 279) Hydantoin(C(O)-(D-Arg-Gly))-c(Cys-Glu- 18.0 17.1 0.160 2710 His-D-Phe-Arg-Trp-Cys)-NH₂ (SEQ ID NO: 278) Hydantoin(C(O)-(Gly-D-Arg))-c(Cys-Glu- 12.9 10.3 0.125 7440 His-D-Phe-Arg-Trp-Cys)-NH₂ (SEQ ID NO: 287) Hydantoin(C(O)-(Arg-Gly))-c(Cys-Glu-His- 8.83 7.86 0.0979 4010 D-Phe-Arg-Trp-Cys)-NH₂ (SEQ ID NO: 278) Hydantoin(C(O)-(Gly-Arg))-c(Cys-Glu-His- 9.97 3.63 0.0687 335 D-Phe-Arg-Trp-Cys)-NH₂ (SEQ ID NO: 285) Hydantoin(C(O)-(Arg-Gly))-c(Cys-D-Ala- 8.81 18.2 0.503 3560 His-D-Phe-Arg-Trp-Cys)-NH₂ (SEQ ID NO: 279) Hydantoin(C(O)-(D-Arg-Gly))-c(Cys-D- 11.5 23.2 0.513 3950 Ala-His-D-Phe-Arg-Trp-Cys)-NH₂ (SEQ ID NO: 279) Hydantoin(C(O)-(Gly-D-Arg))-c(Cys-D- 7.53 11.6 0.435 9840 Ala-His-D-Phe-Arg-Trp-Cys)-NH₂ (SEQ ID NO: 288) Hydantoin(C(O)-(Gly-Arg))-c(Cys-D-Ala- 8.85 5.17 0.599 3610 His-D-Phe-Arg-Trp-Cys)-NH₂ (SEQ ID NO: 286) Hydantoin(C(O)-(Arg-Gly))-c(Cys-D-Ala- 96.6 13.1 21.2 103 His-D-2-Nal-Arg-Trp-Cys)-NH₂ (SEQ ID NO: 282) Formula (VII) Compounds c[Hydantoin(C(O)-(Aib-Cys))-D-Ala-His-D- — 6.28 0.407 — Phe-Arg-Trp-Cys]-NH₂ (SEQ ID NO: 290) c[Hydantoin(C(O)-(Val-Cys))-D-Ala-His-D- — 3.77 0.214 — Phe-Arg-Trp-Cys]-NH₂ (SEQ ID NO: 290) c[Hydantoin(C(O)-(Leu-Cys))-D-Ala-His-D- — 4.72 0.428 — Phe-Arg-Trp-Cys]-NH₂ (SEQ ID NO: 290) c[Hydantoin(C(O)-(Ile-Cys))-D-Ala-His-D- — 8.51 1.85 — Phe-Arg-Trp-Cys]-NH₂ (SEQ ID NO: 290) c[Hydantoin(C(O)-(A6c-Cys))-D-Ala-His-D- — 5.66 1.72 — Phe-Arg-Trp-Cys]-NH₂ (SEQ ID NO: 290) c[Hydantoin(C(O)-(Gly-Cys))-Glu-His-D- 14.5 21.8 0.576 1780 Phe-Arg-Trp-Cys]-NH₂ (SEQ ID NO: 291)

TABLE 12 cAMP Bioassay Data for Selected Compounds EC₅₀ EC₅₀ EC₅₀ EC₅₀ Compound hMC1-R hMC3-R hMC4-R hMC5-R Ac-Tyr-Arg-c(Cys-D-Ala- 6.42 2.39 0.194 1540 His-D-Phe-Arg-Trp-Cys)- NH₂ (SEQ ID NO: 292) Ac-2-Nal-Arg-c(Cys-D- 9.66 6.11 0.275 1730 Ala-His-D-Phe-Arg-Trp- Cys)-NH₂ (SEQ ID NO: 292) Ac-1-Nal-Arg-c(Cys-D- 8.67 4.21 0.363 1320 Ala-His-D-Phe-Arg-Trp- Cys)-NH₂ (SEQ ID NO: 292) Ac-Trp-Arg-c(Cys-D-Ala- 5.78 3.95 0.219 2580 His-D-Phe-Arg-Trp-Cys)- NH₂ (SEQ ID NO: 292)

In Vivo Studies

Compounds of the present invention can be and were tested for an effect upon insulin resistance and/or body weight according to the following procedures. One skilled in the art would know that procedures similar to those described herein may be used to assay the effect of the compounds of the invention upon insulin resistance and/or body weight.

Ligand compounds activating melanocortin receptors tested in the in vivo studies were as follows (Table 13):

TABLE 13 Ligand Code Structure Compound A Ac-Arg-c(Cys-D-Ala-His-D-Phe-Arg-Trp- Cys)-NH₂ SEQ ID NO: 50 Compound B Hydantoin(C(O)-(Arg-Gly))-c(Cys-Glu- His-D-Phe-Arg-Trp-Cys)-NH₂ (SEQ ID NO: 278)

Acute Feeding Experiments (Fasting)

Male Sprague Dawley rats (250 g) were housed in individual cages and maintained under 12:12 hour light:dark conditions. The rats were fasted for 18 hours prior to the start of the experiment with water available ad libitum. At time 0, the rats were injected subcutaneously (sc) with selected compounds at doses of 100 nmole/kg, or with vehicle, and were provided with food. Individual food consumption was measured at about 2, 4 and 6 hours after injection. Data for selected compounds of the invention are reported in FIG. 1.

Chronic Feeding Experiments

Male, Sprague Dawley rats that had been fed either a normal diet (300 g; Research Diets 12450) or a high fat diet (400 g; Research Diets 12451) for 10 weeks prior to the start of the experiment were housed in individual cages and maintained under 12:12 hour light:dark conditions with both food and water available ad libitum. The rats were anesthetized and implanted subcutaneously with an osmotic mini pump (Alzet, Cupertino, Calif.). The pumps delivered either Compound A or Compound B at doses of 75, 300 or 1200 nmole/kg/day, or vehicle for 7 days. Individual body weight and food consumption were measured daily.

On day 7 rats were anesthetized and fit with a jugular-right atrial cannula. On day 8 an iv glucose tolerance test was performed and blood samples were withdrawn into heparinized syringes at time −10 and 0. Immediately after the time 0 blood sample, the rats were injected with glucose (1 g/kg) via the indwelling cannula. Subsequent blood samples were withdrawn at 2.5, 5, 10, 20 and 40 minutes later. Plasma levels of glucose (Diagnostic Chemicals Limited) and insulin (Alpco) were determined by commercially available kits. Results are shown in FIGS. 2A-D and 3A-D.

Glucose Tolerance Tests

Male, C57BL/6 mice that had been fed either a normal diet (30 g; Research Diets 12450) or a high fat diet (45 g; Research Diets 12452) for 12 weeks prior to the start of the experiment were housed in individual cages and maintained under 12:12 hour light:dark conditions with both food and water available ad libitum. The mice were anesthetized and implanted subcutaneously with an osmotic mini pump (Alzet, Cupertino, Calif.). The pumps delivered Compound A at doses of 200, 600 or 1800 nmole/kg/day, or vehicle for 14 days. On day 14 the mice were fasted for 18 hours or overnight. On day 15 an glucose tolerance test was performed by injecting the mice with glucose (2 g/kg) ip. Blood samples were taken by tail stick at 0, 15, 30, 60 and 180 minutes after the glucose injection and blood glucose level was measured using an Accu-Chek glucometer. Results are shown in FIG. 4.

Male, Lep^(ob)/Lep^(ob) mice (50 g) were group housed maintained under 12:12 hour light:dark conditions with both food and water available ad libitum. The mice were fasted for 18 hours or overnight and an ip glucose tolerance test was performed. Mice were injected with Compound A ip at a dose of 6.4 μmole/kg at −15 minutes and a blood sample was taken by tail stick. At time 0 mice were injected ip with glucose (1 g/kg) and blood samples were taken by tail stick at 0, 15, 30, 60 and 90 minutes later and blood glucose level was measured using Glucometer Elite XL (Bayer Corporation). Results are shown in FIG. 5.

ADMINISTRATION AND USE

The peptides of this invention can be provided in the form of pharmaceutically acceptable salts. Examples of such salts include, but are not limited to, those formed with organic acids (e.g., acetic, lactic, maleic, citric, malic, ascorbic, succinic, benzoic, methanesulfonic, toluenesulfonic, or pamoic acid), inorganic acids (e.g., hydrochloric acid, sulfuric acid, or phosphoric acid), and polymeric acids (e.g., tannic acid, carboxymethyl cellulose, polylactic, polyglycolic, or copolymers of polylactic-glycolic acids). A typical method of making a salt of a peptide of the present invention is well known in the art and can be accomplished by standard methods of salt exchange. Accordingly, the TFA salt of a peptide of the present invention (the TFA salt results from the purification of the peptide by using preparative HPLC, eluting with TFA containing buffer solutions) can be converted into another salt, such as an acetate salt, by dissolving the peptide in a small amount of 0.25 N acetic acid aqueous solution. The resulting solution is applied to a semi-prep HPLC column (Zorbax®, 300 SB, C-8). The column is eluted with: (1) 0.1N ammonium acetate aqueous solution for 0.5 hours; (2) 0.25N acetic acid aqueous solution for 0.5 hours; and (3) a linear gradient (20% to 100% of solution B over 30 minutes) at a flow rate of 4 ml/min (solution A is 0.25N acetic acid aqueous solution; solution B is 0.25N acetic acid in acetonitrile/water, 80:20). The fractions containing the peptide are collected and lyophilized to dryness.

As is well known to those skilled in the art, the known and potential uses of peptides with melanocortin receptor (MC-R) agonist or antagonist activity is varied and multitudinous, thus the administration of the compounds of this invention for purposes of eliciting an agonist effect can have the same effects and uses as melanocortin itself.

Accordingly, the present invention includes within its scope pharmaceutical compositions comprising, as an active ingredient, at least one of the compounds of formula (I) in association with a pharmaceutically acceptable carrier.

The dosage of active ingredient in the compositions of this invention may be varied; however, it is necessary that the amount of the active ingredient be such that a suitable dosage form is obtained. The selected dosage depends upon the desired therapeutic effect, on the route of administration, and on the duration of the treatment. In general, an effective dosage for the activities of this invention is in the range of 1×10⁻⁷ to 200 mg/kg/day, preferably 1×10⁴ to 100 mg/kg/day which can be administered as a single dose or divided into multiple doses.

The compounds of this invention can be administered by oral, parenteral (e.g., intramuscular, intraperitoneal, intravenous or subcutaneous injection, or implant), nasal, vaginal, rectal, sublingual or topical routes of administration and can be formulated with pharmaceutically acceptable carriers to provide dosage forms appropriate for each route of administration.

Solid dosage forms for oral administration include capsules, tablets, pills, powders and granules. In such solid dosage forms, the active compound is admixed with at least one inert pharmaceutically acceptable carrier such as sucrose, lactose, or starch. Such dosage forms can also comprise, as is normal practice, additional substances other than such inert diluents, e.g., lubricating agents such as magnesium stearate. In the case of capsules, tablets and pills, the dosage forms may also comprise buffering agents. Tablets and pills can additionally be prepared with enteric coatings.

Liquid dosage forms for oral administration include pharmaceutically acceptable emulsions, solutions, suspensions, syrups, the elixirs containing inert diluents commonly used in the art, such as water. Besides such inert diluents, compositions can also include adjuvants, such as wetting agents, emulsifying and suspending agents, and sweetening, flavoring and perfuming agents.

Preparations according to this invention for parenteral administration include sterile aqueous or non-aqueous solutions, suspensions, or emulsions. Examples of non-aqueous solvents or vehicles are propylene glycol, polyethylene glycol, vegetable oils, such as olive oil and corn oil, gelatin, and injectable organic esters such as ethyl oleate. Such dosage forms may also contain adjuvants such as preserving, wetting, emulsifying, and dispersing agents. Preparations may be sterilized by, for example, filtration through a bacteria-retaining filter, by incorporating sterilizing agents into the compositions, by irradiating the compositions, or by heating the compositions. Preparations can also be manufactured in the form of sterile solid compositions which can be dissolved in sterile water or some other sterile injectable medium immediately before use.

Compositions for rectal or vaginal administration are preferably suppositories which may contain, in addition to the active substance, excipients such as cocoa butter or a suppository wax.

Compositions for nasal or sublingual administration are also prepared with standard excipients well known in the art.

Further, a compound of this invention can be administered in a sustained release composition such as those described in the following patents and patent applications. U.S. Pat. No. 5,672,659 teaches sustained release compositions comprising a bioactive agent and a polyester. U.S. Pat. No. 5,595,760 teaches sustained release compositions comprising a bioactive agent in a gelable form. U.S. Pat. No. 5,821,221 teaches polymeric sustained release compositions comprising a bioactive agent and chitosan. U.S. Pat. No. 5,916,883 teaches sustained release compositions comprising a bioactive agent and cyclodextrin. The teachings of the foregoing patents and applications are incorporated herein by reference. 

1-35. (canceled)
 36. A method of treating insulin resistance in a subject in need thereof, comprising administration of an effective amount of D-Phe-c(Cys-His-D-(Et)Tyr-hArg-Bip-β-Ala-D-Cys)-Thr-NH₂ (SEQ ID NO:26) or a pharmaceutically acceptable salt thereof.
 37. The method of claim 36, wherein said subject is a child.
 38. The method of claim 37, wherein the child is obese.
 39. The method of claim 37, wherein the child is normal weight or lean.
 40. The method of claim 37, wherein the child suffers from Type II diabetes.
 41. The method of claim 36, wherein said subject is an adult.
 42. The method of claim 36, wherein said subject is an elderly adult.
 43. The method of claim 36, wherein the D-Phe-c(Cys-His-D-(Et)Tyr-hArg-Bip-β-Ala-D-Cys)-Thr-NH₂ (SEQ ID NO:26) or a pharmaceutically acceptable salt thereof is formulated as a pharmaceutical composition.
 44. The method of claim 43, wherein said pharmaceutical composition is a sustained release composition.
 45. The method of claim 36, wherein said administration is oral, subcutaneous, intraperitoneal, intramuscular, intravenous, rectal, transdermal or intranasal.
 46. The method according to claim 36, wherein said administration is continuous.
 47. A method of treating insulin resistance in a subject in need thereof, comprising administration of an effective amount of a compound selected from the group consisting of: c[Hydantoin(C(O)-(Asp-His))-D-Phe-Arg-Trp-Lys]-NH₂ (SEQ ID NO: 274) c[Hydantoin(C(O)-(Asp-A³c))-D-Phe-Arg-Trp-Lys]-NH₂; (SEQ ID NO: 274) c[Hydantoin(C(O)-(Asp-A⁵c))-D-Phe-Arg-Trp-Lys]-NH₂; (SEQ ID NO: 274) c[Hydantoin(C(O)-(Asp-A⁶c))-D-Phe-Arg-Trp-Lys]-NH₂; (SEQ ID NO: 274) or a pharmaceutically acceptable salt thereof.
 48. The method of claim 47, wherein said subject is a child.
 49. The method of claim 47, wherein said subject is an adult.
 50. The method of claim 48, wherein the child is obese.
 51. The method of claim 48, wherein the child suffers from Type II diabetes.
 52. The method of claim 47, wherein the compound or a pharmaceutically acceptable salt thereof is formulated as a pharmaceutical composition.
 53. The method of claim 52, wherein said pharmaceutical composition is a sustained release composition.
 54. The method of claim 47, wherein said administration is oral, subcutaneous, intraperitoneal, intramuscular, intravenous, rectal, transdermal or intranasal.
 55. The method according to claim 47, wherein said administration is continuous. 